2022/08/11 更新

写真a

ワカオ シンジ
若尾 真治
所属
理工学術院 先進理工学部
職名
教授

兼担

  • 理工学術院   大学院先進理工学研究科

  • 附属機関・学校   グローバルエデュケーションセンター

学内研究所等

  • 2020年
    -
    2022年

    理工学術院総合研究所   兼任研究員

  • 2014年
    -
    2023年

    太陽光発電システム研究所   プロジェクト研究所所長

学歴

  • 1991年04月
    -
    1993年03月

    早稲田大学   理工学研究科   電気工学専攻・博士後期課程  

  • 1989年04月
    -
    1991年03月

    早稲田大学   理工学研究科   電気工学専攻・修士課程  

  • 1985年04月
    -
    1989年03月

    早稲田大学   理工学部   電気工学科  

学位

  • 早稲田大学   博士(工学)

  • 早稲田大学   工学修士

経歴

  • 2006年04月
    -
    継続中

    早稲田大学   理工学術院   教授

  • 2016年09月
    -
    2020年09月

    早稲田大学   先進理工学部・先進理工学研究科   学部長兼研究科長

  • 1998年04月
    -
    2006年03月

    早稲田大学   理工学部   助教授

  • 1996年04月
    -
    1998年03月

    早稲田大学   理工学部   専任講師

  • 1995年04月
    -
    1996年03月

    早稲田大学   理工学総合研究センター   客員講師

  • 1993年04月
    -
    1995年03月

    早稲田大学   理工学部   助手

▼全件表示

所属学協会

  •  
     
     

    日本計算工学会

  •  
     
     

    日本大陽エネルギー学会

  •  
     
     

    IEEE (The Institute of Electrical and Electronics Engineers)

  •  
     
     

    電気学会

 

研究分野

  • 電力工学

研究キーワード

  • 電磁界解析、数値解析、最適化設計、電気機器、電気鉄道、再生可能エネルギー、太陽光発電、エネルギーマネジメント、電気エネルギー工学(発生・変換・貯蔵、省エネルギーなど)、シミュレーション工学、数理工学(数理的解析・計画・設計)

論文

  • Steady-State Analysis of Electric Machines Using the TP-EEC Method Based on Time-Periodic Conditions in a Rotational Reference Frame

    Hiroyuki Kaimori, Yasuhito Takahashi, Shinji Wakao

    IEEJ Journal of Industry Applications   11 ( 3 ) 458 - 466  2022年05月

    DOI

  • Renovating a house to aim for net-zero energy, thermal comfort, energy self-consumption and behavioural adaptation: A method proposed for ENEMANE HOUSE 2017

    Reina Oki, Yugo Tsuneoka, Shingo Yamaguchi, Soma Sugano, Naoya Watanabe, Takashi Akimoto, Yasuhiro Hayashi, Shinji Wakao, Shin-ichi Tanabe

    ENERGY AND BUILDINGS   201   183 - 193  2019年10月  [査読有り]

     概要を見る

    In Japan, low thermal insulation performance in existing houses is a considerable issue that may lead to health problems. Therefore, it is necessary to acquire technologies and knowledge regarding thermal insulation renovation. On the other hand, with the spread of photovoltaic panels, urban scale energy management and self-consumption have become important. The purpose of this study is to introduce a net-zero energy house which was designed, built, and analyzed by the team of Waseda University and Shibaura Institute of Technology in the ENEMANE HOUSE 2017 competition. The team proposed a renovation method which insert highly insulated walls into the existing structure, creating not only highly insulated areas but also non-insulated areas called "loggias." By opening and closing the windows of the loggia according to the season, it functions as a passive system and enables residents' behavioural adaptation to the environment. On the other hand, to aim for self-consumption and leveling of reverse power flow, a heat pump water heater and a storage battery were operated according to solar radiation prediction. Actual measurements confirmed the implementation and effect of this operational method. Moreover, the energy consumption was greatly reduced, while thermal comfort was maintained by thermal insulation and efficient equipment introduction. (C) 2019 The Authors. Published by Elsevier B.V.

    DOI

  • 既存工業化住宅を用いた改修型ゼロ・エネルギーハウスの提案

    中川 純, 池原 靖史, 渡辺 直哉, 小林 達宏, 田辺 新一, 秋元 孝之, 林 泰弘, 若尾 真治, 常岡 優吾, 山口 真吾, 大木 玲奈, 菅野 颯馬, 野元 彬久, 丸山 由香, 荒木 菜那, 山品 太輝

    日本建築学会技術報告集   ( 59 ) 239 - 242  2019年02月  [査読有り]

     概要を見る

    <p>Saving energy in the residential is required under the influence of global warming and electricity shortage caused by natural disaster in Japan. For the purpose of promoting zero energy house, "ENEMANE HOUSE 2017", a competition of Zero-Energy House was held. This paper shows the overview of the building and equipment planning, and also the evaluation of thermal environment and energy in the zero energy house which the consortium of Waseda University and Shibaura Institute of Technology proposed in the competition. This zero energy house demonstrates a method of renovation of housing using low-insulated outer wall of an existing industrialized house. The aim of the facility planning was not only the compatibility of energy-saving and comfort but also the increase in self-consumption of surplus power. </p>

    DOI CiNii

  • Distributed Energy Management for Comprehensive Utilization of Residential Photovoltaic Outputs

    Yu Fujimoto, Hiroshi Kikusato, Shinya Yoshizawa, Shunsuke Kawano, Akira Yoshida, Shinji Wakao, Noboru Murata, Yoshiharu Amano, Shin-ichi Tanabe, Yasuhiro Hayashi

    IEEE TRANSACTIONS ON SMART GRID   9 ( 2 ) 1216 - 1227  2018年03月

     概要を見る

    The introduction of photovoltaic power systems is being significantly promoted. This paper proposes the implementation of a distributed energy management framework linking demand-side management systems and supply-side management system under the given time-of-use pricing program for efficient utilization of photovoltaic power outputs; each system implements a consistent management flow composed of forecasting, operation planning, and control steps. In our framework, demand-side systems distributed in the electric distribution network manage individual energy consumption to reduce the residential operating cost by utilizing the residential photovoltaic power system and controllable energy appliances so as not to inconvenience residents. On the other hand, the supply-side system utilizes photovoltaic power maximally while maintaining the quality of electric power. The effectiveness of the proposed framework is evaluated on the basis of an actual Japanese distribution network simulation model from both the supply-side and demand-side viewpoints.

    DOI

  • Improvement of torque characteristics for a synchronous reluctance motor using MMA-based topology optimization method

    Yoshifumi Okamoto, Reona Hoshino, Shinji Wakao, Tomonori Tsuburaya

    IEEE Transactions on Magnetics   54 ( 3 )  2018年03月

     概要を見る

    Because a synchronous reluctance motor (SynRM) does not require permanent magnets, its industrial applications focus on lowering manufacturing costs. However, the SynRM has disadvantages. It experiences a lower average torque and oscillations derived from torque ripple compared to a permanent magnet-based motor. Therefore, the improvement of torque characteristics is investigated using topology optimization (TO) method which allows a greater variety of rotor structure than the shape optimization technique and does not require the concrete initial structure. Although the level set method is well known among TO methods, the smoothed-heaviside-function-based TO implemented by method of moving asymptotes is more suitable due to the feasibility of implementing the physical structure and the convergence speed. In this paper, the reasonable structure of rotor core in SynRM is investigated using TO method to improve the torque characteristic.

    DOI

  • Method for determining voltage control parameters of low-voltage regulator using forecast interval of photovoltaic output

    Masaya Kobayashi, Hiroshi Kikusato, Jun Yoshinaga, Yu Fujimoto, Nao Kumekawa, Shinji Wakao, Yasuhiro Hayashi, Noriyuki Motegi, Yusuke Yamashita

    2017 IEEE PES Innovative Smart Grid Technologies Conference Europe, ISGT-Europe 2017 - Proceedings   2018-   1 - 6  2018年01月

     概要を見る

    A low-voltage regulator (LVR) is investigated as a countermeasure for voltage violation caused by the integration of photovoltaic (PV) systems in distribution systems. To achieve appropriate voltage control by the LVR, the appropriate control parameters need to be determined. We have proposed schemes to determine the appropriate control parameters using PV forecast profiles. In a previous work, the control parameters were determined on the basis of one-scenario PV forecast, which derives one forecast value in each time step. However, voltage violation could not be avoided by this method in a time step with a large forecast error. In this paper, we propose a method for determining the voltage control parameters of the LVR based on the forecast interval of the PV outputs to quantitatively consider the PV forecast error. The numerical simulation results show that the proposed method can reduce the amount of voltage deviation compared with the conventional method.

    DOI

  • Design optimization of primary core in induction heating roll by the combination of 2D level-set method and 3D coupled magnetic-Thermal FEM

    Kazuki Hirono, Reona Hoshino, Tsuyoshi Kamiya, Shinji Wakao, Yoshifumi Okamoto, Woojin Jeon

    IEEJ Journal of Industry Applications   7 ( 1 ) 64 - 72  2018年

     概要を見る

    We present a novel practical design optimization for the primary core in an induction heating roll, which significantly affects the heating performance. To optimize the 3D eddy current field problem within an acceptable CPU time, we effectively combine 2D magnetostatic optimization and 3D coupled magnetic-thermal FEM. For the 2D optimization, we adopt the level-set method, which has an advantage of being able to derive a feasible shape. However, the disadvantage is that its result occasionally falls into a local optimal solution. To overcome this disadvantage, we propose conducting the initial conceptual design with the linear level-set method before using the nonlinear level-set method to expand the search domain. Furthermore, we incorporate the parallelized move-limit strategy into the level-set method to prevent the configuration from undergoing excess deformation by the operation for the area constraint. Finally, the 2D optimal shape obtained using our new level-set method is converted into a straight line cross-sectional configuration to improve manufacturability, and the final 3D design is created with slits. The final 3D design obtained as a result of the 3D FEM successfully improves both the heating speed and temperature uniformity on the surface of the heating part under the same conditions of input AC current and material volume.

    DOI

  • Prediction interval estimation of 10 second PV output fluctuation in the next day

    Nao Kumekawa, Hayato Homma, Shinji Wakao

    IEEJ Transactions on Power and Energy   138 ( 1 ) 5 - 13  2018年

     概要を見る

    Photovoltaic(PV) power generation systems have gained much attention against a background of energy and environmental problems. However, the output of PV system depends on climate conditions. Therefore, a mass introduction of PV results in the power quality deterioration in the distribution system. To overcome the difficulty, it is effective to introduce Low Voltage Regulator(LVR) to the distribution system. However, the application of LVR brings a new problem, i.e., a control delay for activating the tap after detecting the fluctuation. With this background, to provide more useful predictive information in advance, this paper deals with a novel prediction interval estimation method of 10 second PV fluctuation with two-dimensional kernel density estimation. We also carry out the prediction by using several different methods for comparison, e.g., the conventional method with one-dimensional kernel density estimation and the application of various smoothing methods to this conventional method. Finally, some numerical results, which demonstrate the effectiveness of the proposed method on the basis of several indexes, are also presented.

    DOI

  • 自立的運用を目指した既存改修型ゼロ・エネルギーハウスの提案と実証評価 その2 設備・制御計画とエネルギーに関する冬季実測結果

    大木 玲奈, 田辺 新一, 秋元 孝之, 林 泰弘, 常岡 優吾, 若尾 真治, 廣川 由樹, 山口 真吾, 菅野 颯馬, 中川 純, 渡辺 直哉, 小林 達宏

    空気調和・衛生工学会大会 学術講演論文集   2018 ( 0 ) 189 - 192  2018年  [査読有り]

     概要を見る

    <p>一般社団法人環境共創イニシアチブが開催する「エネマネハウス2017」に早稲田大学、芝浦工業大学の2大学連合で参加し、本事業を通して改修型ZEHの設計・施工・実証を行った。実証住宅に搭載したヒートポンプ給湯器と蓄電池を日射量の予測値に応じて運用することで、余剰電力をできるだけ自家消費する自立的なエネルギー運用を提案した。本報では、実証住宅の設備・制御計画、日射量予測システム、エネルギー運用の冬季実測結果について述べる。</p>

    DOI CiNii

  • Prediction Interval Estimation of Demand Curve in Electric Power Distribution System

    Tomohide Yamazaki, Shinji Wakao, Hirokazu Ito, Tsuneyo Sano

    ELECTRICAL ENGINEERING IN JAPAN   202 ( 2 ) 12 - 23  2018年01月

     概要を見る

    In a distribution line, power system control and power equipment investment are planned based on a measured power system current. However, recently the mass introduction of photovoltaic (PV) make it difficult for us to precisely measure the demand curve that is a current consumed by electrical equipment because the reversal power flow from PV systems is superposed. Therefore, the prediction of demand curves of distribution line is indispensable for power system management. In addition, it is also necessary to estimate the reliability of the predicted values as well as predicted current itself. In this paper, we propose the estimation method of the prediction interval that is the index of reliability based on the past demand curve database. The feature of the proposed method based on Just-In-Time (JIT) modeling make it possible for us to accurately estimate the prediction interval by the normalized database of demand curve. In this paper, some numerical examples are presented, which demonstrate the effectiveness of the proposed method. (C) 2017 Wiley Periodicals, Inc.

    DOI

  • Topology optimization of induction heating model using sequential linear programming based on move limit with adaptive relaxation

    Hiroshi Masuda, Yutaro Kanda, Yoshifumi Okamoto, Kazuki Hirono, Reona Hoshino, Shinji Wakao, Tomonori Tsuburaya

    Open Physics   15 ( 1 ) 845 - 850  2017年12月

     概要を見る

    It is very important to design electrical machineries with high efficiency from the point of view of saving energy. Therefore, topology optimization (TO) is occasionally used as a design method for improving the performance of electrical machinery under the reasonable constraints. Because TO can achieve a design with much higher degree of freedom in terms of structure, there is a possibility for deriving the novel structure which would be quite different from the conventional structure. In this paper, topology optimization using sequential linear programming using move limit based on adaptive relaxation is applied to two models. The magnetic shielding, in which there are many local minima, is firstly employed as firstly benchmarking for the performance evaluation among several mathematical programming methods. Secondly, induction heating model is defined in 2-D axisymmetric field. In this model, the magnetic energy stored in the magnetic body is maximized under the constraint on the volume of magnetic body. Furthermore, the influence of the location of the design domain on the solutions is investigated.

    DOI

  • Topology optimization of IH-equipment using heaviside function in 2-D axisymmetric electromagnetic field

    Hiroshi Masuda, Yutaro Kanda, Yoshifumi Okamoto, Kazuki Hirono, Reona Hoshino, Shinji Wakao, Tomonori Tsuburaya

    2017 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering, ISEF 2017    2017年10月

     概要を見る

    Topology optimization is one of the mathematical methods for finding the optimal structure of electrical machinery. Because topology optimization can make a design with much higher degree of freedom in terms of structure than other optimization methods, there is a possibility for achieving a completely new shape that is not limited to the conventional model. The optimized structure is strongly dependent on the characteristic function which is an explicit function with respect to the design variable. To identify the practical topology in which the gray scale elements do not exist as much as possible, Heaviside function is suitable to suppress the generation of gray scale. In this paper, Heaviside function is applied to the IH equipment problem, and both influences of the difference between single and multiple design domain and the difference of the constraint value of the magnetic body volume on optimal solution are particularly investigated.

    DOI

  • Convergence Acceleration of Topology Optimization Based on Constrained Level Set Function Using Method of Moving Asymptotes in 3-D Nonlinear Magnetic Field System

    Yoshifumi Okamoto, Hiroshi Masuda, Yutaro Kanda, Reona Hoshino, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   53 ( 6 )  2017年06月

     概要を見る

    Topology optimization (TO) has advantages over shape optimization; for example, the design space is wider and the degrees of the shape freedom is larger. The convergence characteristic in the conventional level set (LS) method is slow because of the limitation of the time step size that is used for solving the simplified Hamilton-Jacobi equation, which is normally defined as the width of one finite element in the design domain. To overcome this difficulty, convergence acceleration using the method of moving asymptotes is investigated. The performance of the proposed method is compared with the conventional LS method for a 3-D TO problem regarding the magnetic shielding and an interior permanent magnet motor in a 3-D nonlinear magnetostatic field.

    DOI

  • Voltage Control Method Utilizing Solar Radiation Data in High Spatial Resolution for Service Restoration in Distribution Networks with PV

    Shunsuke Kawano, Yu Fujimoto, Shinji Wakao, Yasuhiro Hayashi, Hideaki Takenaka, Hitoshi Irie, Takashi Y. Nakajima

    JOURNAL OF ENERGY ENGINEERING   143 ( 3 )  2017年06月

     概要を見る

    This paper proposes a voltage control method during service restoration in the distribution networks with photovoltaic (PV) generator systems. In the current distribution automation system (DAS) process in Japan, voltage dips and surges occur during service restoration because PVs are disconnected simultaneously after a fault and subsequently reconnected after service restoration. However, in the current DAS, voltage regulators such as an on-load tap changer (OLTC) and step voltage regulators (SVRs) are not controlled during service restoration. The proposed DAS estimates the voltage in a distribution network during service restoration, and it controls the tap position of OLTC and/or SVRs according to the predicted voltage. The numerical simulation results using a real-world distribution system model on a real map and PV output profiles derived by actual square kilometer solar radiation data will be shown. Those results indicate that the proposed DAS prevents voltage deviation that occurs as long as the current DAS is used. The results also show high spatial resolution PV output data are needed to prevent voltage deviation absolutely. (C) 2016 American Society of Civil Engineers.

    DOI

  • Level-set-function-based topology optimization supported by the method of moving asymptotes in a magnetic field problem

    Yoshifumi Okamoto, Shinji Wakao

    IEEE CEFC 2016 - 17th Biennial Conference on Electromagnetic Field Computation    2017年01月

     概要を見る

    Topology optimization (TO) is an attractive design tools for electrical machinery. In particular, the level-set-based TO has been investigated enthusiastically. In this paper, a level-set-based topology optimization method supported by the method of moving asymptotes is proposed to realize fast convergence. The performance of the proposed method is verified in comparison with the conventional level-set-based method, which is composed of both gradient-based-correction and regularization.

    DOI

  • On smoother based on Laplacian method for uneven surface derived from 3-D topology optimization of electrical machinery in magnetic field system

    Yutaro Kanda, Yoshifumi Okamoto, Hiroshi Masuda, Shinji Wakao

    Simulation for Additive Manufacturing 2017, Sinam 2017   2017-October   214 - 215  2017年01月

  • A study on multiply connected domain processing methods in magnetostatic field analysis by boundary integral equations

    Kengo Ryu, Shinji Wakao, Yasuhito Takahashi, Kazuhisa Ishibashi, Koji Fujiwara

    IEEJ Transactions on Power and Energy   137 ( 2 ) 132 - 137  2017年

     概要を見る

    It is difficult to analyze magnetostatic field problems with multiply connected domains by the direct boundary element method (BEM). On the other hand, there are two methods which can solve magnetostatic field problems with multiply connected domains in double layer charge (DLC) formulation. One uses imaginary loop current to calculate exciting scalar potentials and the other uses the direct BEM to calculate exciting scalar potentials. Thus, in this study, we expand the application scope of the above methods to the direct BEM. The direct BEM is widely used with other analysis methods such as the finite element method (FEM). In that respect, it is also effective to be able to analyze magnetostatic field problems with multiply connected domains by the direct BEM. In addition, results comparing the two methods to analyze multiply connected problems in both the DLC formulation and the direct BEM have not been reported. Therefore, we compare those and systematically clarify their characteristics by calculating a toroidal core model.

    DOI

  • 境界積分方程式を用いた静磁界解析における多重連結処理手法に関する一考察

    笠 健悟, 若尾 真治, 髙橋 康人, 石橋 一久, 藤原 耕二

    電気学会論文誌. B   137 ( 2 ) 132 - 137  2017年

     概要を見る

    &lt;p&gt;It is difficult to analyze magnetostatic field problems with multiply connected domains by the direct boundary element method (BEM). On the other hand, there are two methods which can solve magnetostatic field problems with multiply connected domains in double layer charge (DLC) formulation. One uses imaginary loop current to calculate exciting scalar potentials and the other uses the direct BEM to calculate exciting scalar potentials. Thus, in this study, we expand the application scope of the above methods to the direct BEM. The direct BEM is widely used with other analysis methods such as the finite element method (FEM). In that respect, it is also effective to be able to analyze magnetostatic field problems with multiply connected domains by the direct BEM. In addition, results comparing the two methods to analyze multiply connected problems in both the DLC formulation and the direct BEM have not been reported. Therefore, we compare those and systematically clarify their characteristics by calculating a toroidal core model.&lt;/p&gt;

    DOI CiNii

  • Estimation Prediction Interval of Solar Irradiance Based on Just-in-Time Modeling for Photovoltaic Output Prediction

    Tomohide Yamazaki, Hayato Homma, Shinji Wakao, Yu Fujimoto, Yasuhiro Hayashi

    ELECTRICAL ENGINEERING IN JAPAN   195 ( 3 ) 1 - 10  2016年05月

     概要を見る

    Photovoltaic (PV) systems have recently attracted considerable attention in the context of environmental problems, antinuclear power movements, and energy problems. Therefore, the large-scale introduction of PV systems is expected in the near future. But the connection of many PV systems to the power system leads to problems. For example, the system voltage often drifts from the norm when reverse power flows increase. Accordingly, optimal system operation is required in order to make maximum use of solar energy to the maximum by installing energy buffers such as storage batteries. In particular, in forecast information, knowledge of the reliability as well as the predicted solar irradiance is essential for effective operation. In this paper, we propose a way of estimating the prediction interval of solar irradiance as an index of reliability by using just-in-time modeling. We consider the accuracy of the prediction interval under many conditions and derive a high-precision estimation method. In addition, we also discuss about the future subjects of study. (C) 2016 Wiley Periodicals, Inc. Published online in Wiley Online Library (wileyonlinelibrary.com).

    DOI

  • Magnetostatic Shield Analysis by Double-Layer Charge Formulation Using Difference Field Concept

    K. Ryu, T. Yoshioka, S. Wakao, Y. Takahashi, K. Ishibashi, K. Fujiwara

    IEEE TRANSACTIONS ON MAGNETICS   52 ( 3 )  2016年03月

     概要を見る

    This paper proposes a novel accuracy improvement technique for the double-layer charge (DLC) formulation in shielding problems. Although the DLC formulation has advantages over the direct methods from the viewpoint of computational cost, the calculation accuracy can be worse because of cancellation errors. In order to improve the accuracy, we apply a new technique based on the difference field concept. Numerical results, which verify the effectiveness of the proposed method, are presented.

    DOI

  • Topology Optimization Based on Regularized Level-Set Function for Solving 3-D Nonlinear Magnetic Field System With Spatial Symmetric Condition

    Yoshifumi Okamoto, Shinji Wakao, Shuji Sato

    IEEE TRANSACTIONS ON MAGNETICS   52 ( 3 )  2016年03月

     概要を見る

    Topology optimization (TO) is an effective method for producing practical design of electrical machines. TO is conventionally implemented based on the material density; however, this approach can yield a large number of grayscale areas and unfeasible shapes. On the other hand, when the level-set function is applied to the TO of the magnetic field problem, the potential for obtaining a feasible solution improves. This paper implemented a TO method that uses the regularized level-set function to solve the 3-D nonlinear magnetic field problem. Furthermore, a spatial symmetry condition (SSC), which can introduce the mirror and periodic symmetry of the level-set function from the viewpoint of the electromagnetism, is proposed. To achieve symmetry in the electromagnetic field distribution, the validity of the SSC is investigated and confirmed in a 3-D magnetic shielding problem.

    DOI

  • Computational Analysis of Battery Operation in Photovoltaic Systems with Varying Charging and Discharging Rates

    Takuma Arai, Shinji Wakao

    2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     1773 - 1778  2016年

     概要を見る

    In the case of a mass introduction of PV the instability of PV system output leads to a deterioration of power quality in the distribution system. In this research, we focus on the storage battery operation to achieve a balance between power supply and demand, and perform multi-objective optimization. Specifically, we determine the optimal relationship between the storage battery's charging and discharging rates and the required time resolution for ideal optimization results.

    DOI

  • Prediction Interval Estimation of 10 second fluctuation of PV output with Just-In-Time Modeling

    Nao Kumekawa, Hayato Honma, Shinji Wakao

    2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)     1825 - 1830  2016年

     概要を見る

    The Output of photovoltaic (PV) systems depends on weather conditions. Therefore if there is a large introduction of PV systems, the power quality in the distribution system will be affected. One effective solution for this problem is to predict PV output. Although the need for prediction information for short period fluctuation is increasing, it is difficult to directly predict a steep fluctuation on the second time scale. For the prediction information of PV output, we propose the estimation of the prediction interval of the fluctuation widths on a 10 second scale. In this paper, we carry out the prediction by using the conventional method, with one-dimensional kernel density estimation, and the proposed method, with two-dimensional kernel density estimation. Then, we discuss the effectiveness of the proposed method based on several numerical indexes.

    DOI

  • Optimal scheduling for residential PEM fuel cell cogeneration system under uncertainty of PV output and energy demand using MISOCP approach

    Akira Yoshida, Jun Yoshikawa, Yu Fujimoto, Shinji Wakao, Yoshiharu Amano

    ECOS 2016 - Proceedings of the 29th International Conference on Efficiency, Cost, Optimisation, Simulation and Environmental Impact of Energy Systems    2016年

     概要を見る

    © 2016 University of Ljubljana. The degree of operational freedom of home appliances is increasing with introducing controllable demand-side appliances by using Home Energy Management System with some communication standard. This situation increases the demands on methodology achieving customer utility maximization, which is able to plan operational strategies of a variety of appliances under various exogenous variables such as energy demand, outlet temperature, and power output of Photovoltaic power generator. Energy demand and photovoltaic output have some uncertainty or variation in the parameter. The objective of this study is to analyze a solution behavior of an operational planning problem adapting Mixed Integer Second-Order Cone Programming extended from traditional Mixed Integer Linear Programming model. The objective function of the mathematical optimization involves mean and its variance by extracting naturally Markowitz model. Above proposed model is intended to sophisticate robust operational planning method, and is also evaluated on the EMS simulation platform that we are developing. As a result, it is found that involving variance to objective function affects to computational time meaning computational load rather than robustness of planned schedule. Additionally, using several scenario results in more robust schedule than using plausible one scenario.

  • Multi-Objective Design Optimization of Primary Core in Induction Heating Roll by Level-set Method

    Kazuki Hirono, Reona Hoshino, Shinji Wakao, Yoshifumi Okamoto, W. Jeon

    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC)    2016年

     概要を見る

    This paper deals with the multi-objective design optimization of the primary core in induction heating roll in consideration of heating performance, cost, and manufacturability. We effectively carry out the shape optimization of the core by combining the 2D level-set method with the 3D finite element method for the coupled nonlinear magnetic-thermal analysis.

    DOI

  • Multi-objective Optimization of Magnetic Sensor with Conductor Plate for Rail Wheel Detection

    Hiroyuki Kuwahara, Yuva Maruyama, Shinji Wakao, Masahide Takahashi, Makoto Yagi, Tamio Okutani, Yoshifumi Okamoto

    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC)    2016年

     概要を見る

    The axle counter which detects the position of the train is important railway signal device. This paper deals with a multi-objective optimization of the axle counter by 3D magnetic field analysis. In the optimization, we newly propose the introduction of the conductor plate and carry out its design optimization. It is revealed that the shape optimization of conductor plate enables us to well improve the detection performance of the axle counter from the multi-objective point of view.

    DOI

  • Development of Local Expansion Edge Element for Magnetic Field Analysis

    Yuki Wakayama, Yuichiro Hosobuchi, Ryunosuke Shimoyama, Shinji Wakao, Tadashi Tokumasu, Yasuhito Takahashi, Koji Fujiwara

    2016 IEEE CONFERENCE ON ELECTROMAGNETIC FIELD COMPUTATION (CEFC)    2016年

     概要を見る

    In this paper, we propose a novel analysis method with local expantion edge elements, in which the interpolation of the potential in the radial direction is defined besed on the idea of the local expansion. It enables us to accurately analyze the physical quantity in the targeted finite region as more smoothed values.

    DOI

  • 配電系統における実負荷電流の予測信頼区間推定

    山㟢 朋秀, 若尾 真治, 伊藤 広和, 佐野 常世

    電気学会論文誌. B   136 ( 12 ) 848 - 857  2016年

     概要を見る

    &lt;p&gt;In a distribution line, power system control and power equipment investment are planned based on a measured power system current. However, recently the mass introduction of PV make it difficult for us to precisely measure the demand curve that is a current consumed by electrical equipment because the reversal power flow from PV systems is superposed. Therefore, the prediction of demand curves of distribution line is indispensable for power system management. Additionally, it is also necessary to estimate the reliability of the predicted values as well as predicted current itself. In this paper, we propose the estimation method of the prediction interval that is the index of reliability based on the past demand curve database. The feature of the proposed method based on Just-In-Time (JIT) modeling make it possible for us to accurately estimate the prediction interval by the normalized database of demand curve. In this paper, some numerical examples are presented, which demonstrate the effectiveness of the proposed method.&lt;/p&gt;

    DOI CiNii

  • Prediction Interval Estimation of 10 second fluctuation of PV output with Just-In-Time Modeling

    Nao Kumekawa, Hayato Honma, Shinji Wakao

    2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)   2016-November   1825 - 1830  2016年

     概要を見る

    The Output of photovoltaic (PV) systems depends on weather conditions. Therefore if there is a large introduction of PV systems, the power quality in the distribution system will be affected. One effective solution for this problem is to predict PV output. Although the need for prediction information for short period fluctuation is increasing, it is difficult to directly predict a steep fluctuation on the second time scale. For the prediction information of PV output, we propose the estimation of the prediction interval of the fluctuation widths on a 10 second scale. In this paper, we carry out the prediction by using the conventional method, with one-dimensional kernel density estimation, and the proposed method, with two-dimensional kernel density estimation. Then, we discuss the effectiveness of the proposed method based on several numerical indexes.

    DOI

  • Computational Analysis of Battery Operation in Photovoltaic Systems with Varying Charging and Discharging Rates

    Takuma Arai, Shinji Wakao

    2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)   2016-November   1773 - 1778  2016年

     概要を見る

    In the case of a mass introduction of PV the instability of PV system output leads to a deterioration of power quality in the distribution system. In this research, we focus on the storage battery operation to achieve a balance between power supply and demand, and perform multi-objective optimization. Specifically, we determine the optimal relationship between the storage battery's charging and discharging rates and the required time resolution for ideal optimization results.

    DOI

  • モータ電磁騒音低減のための新しいPWMキャリア分散手法

    谷口 峻, 上條 芳武, 安井 和也, 松下 真琴, 結城 和明, 若尾 真治

    電気学会論文誌D(産業応用部門誌)   135 ( 12 ) 1144 - 1152  2015年12月

     概要を見る

    This paper proposes a new pulse width modulation (PWM) carrier distribution technique for reducing motor electromagnetic noise. The proposed method uses only two carrier frequencies and controls PWM harmonics by the transferring probability of the two carrier frequencies. The proposed method is verified by experiments using 0.8kW PMSM.

    DOI CiNii

  • The study of a magnetic-polarity detection method for permanent-magnet reluctance motors

    Shun Taniguchi, Kazuya Yasui, Kazuaki Yuki, Yosuke Nakazawa, Makoto Matsushita, Shinji Wakao

    IEEJ Transactions on Industry Applications   135 ( 6 ) 641 - 647  2015年06月

     概要を見る

    In this paper, a magnetic-polarity detection method for a permanent-magnet reluctance motor (PRM) is presented. The inductance characteristics of a PRM are different from those of common interior permanent-magnet synchronous motors and are verified by an electromagnetic field analysis. Moreover, a novel magnetic-pole detection method is proposed using the inductance characteristics of a PRM. The proposed method is verified by experiments using a 90-kW PMSM.

    DOI

  • Computational Accuracy Enhancement in Magnetic Field Analysis by Using Orthogonalized Infinite Edge Element Method

    Kenta Tsuzaki, Yoshihiro Tawada, Shinji Wakao, Akihisa Kameari, Tadashi Tokumasu, Yasuhito Takahashi, Hajime Igarashi, Koji Fujiwara, Yoshiyuki Ishihara

    ELECTRICAL ENGINEERING IN JAPAN   191 ( 1 ) 20 - 28  2015年04月

     概要を見る

    Electromagnetic phenomena intrinsically spread over an infinite region. Thus, efficient handling of open boundaries is one of the main issues in electromagnetic field computations. This paper deals with the orthogonalized infinite edge element method that efficiently performs precise analysis of the infinite region. In this method, several parameters are used to achieve high accuracy. As one of the parameters, we focus on the reference point and investigate the effect of its position setting on accuracy. We also evaluate the accuracy of the calculated magnetic field in the far region. By applying boundary element method as postprocessing, it is found that high computational accuracy in the region can be effectively achieved.

    DOI

  • Improvement in Computational Accuracy and Convergence Characteristics by Combined Application of Various Infinite Edge Element Configurations

    Ryunosuke Shimoyama, Emi Tsukamoto, Shinji Wakao, Akihisa Kameari

    IEEE TRANSACTIONS ON MAGNETICS   51 ( 3 )  2015年03月

     概要を見る

    The infinite edge element method (IEEM) has been proposed as an effective method for efficiently handling open boundary region, i.e., the air region. In this paper, we present a newly defined infinite element radiated from a reference plane (RPL), and propose the combination method using various infinite element configurations, such as radiated configurations from a reference point, a reference line, and an RPL. By using the proposed hybrid method, we can drastically decrease the number of ill-shaped infinite elements and improve the computational accuracy and convergence characteristics in comparison with the conventional IEEM, especially in the case of flattened analysis models.

    DOI

  • Design Optimization of Magnetic Sensor for Train Detection

    Shogo Yasukawa, Naoko Takagi, Gege Dong, Shinji Wakao, Masahide Takahashi, Makoto Yagi, Tamio Okutani

    IEEE TRANSACTIONS ON MAGNETICS   51 ( 3 )  2015年03月

     概要を見る

    The axle counter as a train detector is one of the important railway signaling devices for accurate and safe train control systems. This paper deals with a design optimization of the axle counter by large-scale magnetic field computations. To efficiently reduce the computational burden in the optimization, we accurately estimate the signaling level by applying infinite edge elements to an extensive air domain, which results in a practical design approach within an acceptable CPU-time.

    DOI

  • Estimation method of prediction interval of solar irradiance based on Just-In-Time modeling for photovoltaic output prediction

    Tomohide Yamazaki, Hayato Homma, Shinji Wakao, Yu Fujimoto, Yasuhiro Hayashi

    IEEJ Transactions on Power and Energy   135 ( 3 ) 160 - 167  2015年03月

     概要を見る

    PV system recently attracts much attention on the back of environmental problems, antinuclear power movements and energy problems. Therefore, a large scale introduction of PV system is expected in the near future. On the other hand, a lot of PV systems connected to the power system bring on some problems. For example, a system voltage often drifts from the norm when the reverse power flow increase. Accordingly, it is necessary to perform an optimal system operation in order to utilize a solar energy to the maximum by installing energy buffers, e.g. storage batteries. Especially, the forecast information i.e., the reliability as well as predicted solar irradiance is essential for the effective operation. In this paper, we propose a way to estimate the prediction interval of the solar irradiance as an index of reliability by using Just-In-Time Modeling (JIT Modeling). We consider the accuracy of the prediction interval under many conditions and derive the high-precision estimation method. In addition, we also talk about the future outlook of this study.

    DOI

  • Material-Density-Based Topology Optimization With Magnetic Nonlinearity by Means of Stabilized Sequential Linear Programming: SLPSTAB

    Yoshifumi Okamoto, Yu Matsubayashi, Shinji Wakao, Shuji Sato

    IEEE TRANSACTIONS ON MAGNETICS   51 ( 3 )  2015年03月

     概要を見る

    The nonlinear magnetic properties of an iron core should be considered when topology optimization (TO) is applied to a realistic problem. However, a scheme for introduction of the magnetic nonlinearity to material-density-based TO has not been rigorously established. In this paper, TO by using material density with magnetic nonlinearity is proposed. The numerical instability of the sequential linear programming method is a well-known topic. The stabilized sequential linear programming method, which realizes the stabilized convergence characteristics of an objective function, is proposed and investigated in the 3-D design problem of a magnetic circuit.

    DOI

  • Effect of PV Output and Load Power Forecast Error on Operation Design of PV System with Storage Battery

    Takayoshi Hayashi, Takahiro Shimoo, Shinji Wakao

    ELECTRICAL ENGINEERING IN JAPAN   190 ( 1 ) 28 - 36  2015年01月

     概要を見る

    In the past, we have proposed battery operations in a photovoltaic (PV) system using PV output and load power forecasts. In the proposed method, we utilized multiobjective optimization for a residential area model that includes a large number of PV systems with storage batteries. To practically demonstrate that the proposed operation effectively improves economic and environmental efficiency, it is indispensable to evaluate the effects of forecast error on the operation design of a PV system with storage battery. In this paper, we propose a method for evaluating the robustness of battery operation taking account of the statistical characteristics of forecast errors. Some numerical examples, which show the validity of the proposed method, are also presented.

    DOI

  • Advantage of a home energy management systems for PV utilization connected to grid

    Akira Yoshida, Akira Yoshida, Shinya Yoshizawa, Shinya Yoshizawa, Yu Fujimoto, Yu Fujimoto, Noboru Murata, Noboru Murata, Shinji Wakao, Shinji Wakao, Shin Ichi Tanabe, Shin Ichi Tanabe, Yasuhiro Hayashi, Yasuhiro Hayashi, Yoshiharu Amano, Yoshiharu Amano

    ECOS 2015 - 28th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems    2015年01月

     概要を見る

    Residential houses are in the process of introducing power generators such as photovoltaic (PV) power generators and fuel cell cogeneration systems. Under current laws in Japan, surplus electricity from a residential PV system can be sold by feeding it back into the electrical grid. However, when a lot of neighboring power generators make and feed back electricity at the same time, there is an issue of an upper voltage violation of the provisions of the laws and regulations relating to the Electricity Business Act in the distribution system of the electrical grid. The issue has been solved by stopping power generators when they reach an upper voltage limit, 107V. Another solution is to acknowledge demand response signal from electrical grid operator to store electricity in residential batteries using Home Energy Management System (HEMS). The research question is that how to collaborate HEMS and Grid Energy Management System (GEMS). This paper developed an evaluation framework for the cooperative behavior between HEMS and GEMS. Using this evaluation framework, this paper demonstrated the optimal operational strategy of HEMS including PV in the case that HEMS is informed voltage profile from GEMS, and also assessed amount of PV suppression quantitatively in residential sector in practical aspect.

  • Economic evaluations of residential energy systems based on the prediction-operational planning-control method using time-of-use prices

    Ryohei Ogata, Akira Yoshida, Akira Yoshida, Yu Fujimoto, Yu Fujimoto, Noboru Murata, Noboru Murata, Shinji Wakao, Shinji Wakao, Shin Ichi Tanabe, Shin Ichi Tanabe, Yoshiharu Amano, Yoshiharu Amano

    ECOS 2015 - 28th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems    2015年01月

     概要を見る

    Demand-side electricity saving is an important factor in the reduction of the installed capacity of power-supply facilities. In order to save electricity automatically while maintaining comfort levels, home energy management systems (HEMS) have attracted attention. These systems can control residential energy equipment cooperatively to reduce electricity consumption while considering benefits to consumers. Although many researchers have evaluated HEMS, no one has conducted a study which considers the control of various types of residential energy equipment in real time along with the uncertainties of energy demands. This paper proposes a single HEMS method which connects prediction, operational planning and control steps and enables the evaluation of operational planning methods of HEMS connected with many kinds of residential energy equipment currently in use in Japan while considering the uncertainties. The purpose of this study is to evaluate the economic potential of residential energy systems based on the proposed method with the uncertainties of energy demands and photovoltaic (PV) output under time-of-use prices. The results allowed us to establish a framework to quantitatively evaluate the operational planning methods of HEMS with the uncertainties of energy demands and PV output. In addition, the usability of the proposed method was confirmed by comparing the operational costs to those of a reference method.

  • Advantage of a home energy management system for PV utilization connected to grid

    Akira Yoshida, Akira Yoshida, Shinya Yoshizawa, Shinya Yoshizawa, Yu Fujimoto, Yu Fujimoto, Noboru Murata, Noboru Murata, Shinji Wakao, Shinji Wakao, Shin Ichi Tanabe, Shin Ichi Tanabe, Yasuhiro Hayashi, Yasuhiro Hayashi, Yoshiharu Amano, Yoshiharu Amano

    ECOS 2015 - 28th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems    2015年01月

     概要を見る

    Residential houses are in the process of introducing power generators such as photovoltaic (PV) power generators and fuel cell cogeneration systems. Under current laws in Japan, surplus electricity from a residential PV system can be sold by feeding it back into the electrical grid. However, when a lot of neighboring power generators make and feed back electricity at the same time, there is an issue of an upper voltage violation of the provisions of the laws and regulations relating to the Electricity Business Act in the distribution system of the electrical grid. The issue has been solved by stopping power generators when they reach an upper voltage limit, 107V. Another solution is to acknowledge demand response signal from electrical grid operator to store electricity in residential batteries using Home Energy Management System (HEMS). The research question is that how to collaborate HEMS and Grid Energy Management System (GEMS). This paper developed an evaluation framework for the cooperative behavior between HEMS and GEMS. Using this evaluation framework, this paper demonstrated the optimal operational strategy of HEMS including PV in the case that HEMS is informed voltage profile from GEMS, and also assessed amount of PV suppression quantitatively in residential sector in practical aspect.

  • The study of magnetic polarity detection method for permanent magnet reluctance motor

    Shun Taniguchi, Kazuya Yasui, Kazuaki Yuki, Makoto Matsushita, Yosuke Nakazawa, Shinji Wakao

    2015 17TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'15 ECCE-EUROPE)     1 - 10  2015年

     概要を見る

    This paper studies a magnetic polarity detection method for permanent magnet reluctance motor (PRM). Inductance characteristic of PRM is different from that of common interior permanent magnet synchronous motor. The inductance characteristic of PRM is verified by electromagnetic field analysis. Moreover, this paper proposes novel magnetic polarity detection method using the inductance characteristic of PRM. The proposed method is verified by experiments using a 90-kW PRM.

    DOI

  • A Study on the Maximum Use of PV Power in a Residential Community -the case of Utilizing of Demand Response Program-

    Hiroto Kuroiwa, Tomohide Yamazaki, Shinji Wakao, Kei Morita, Yuichi Nakano, Osamu Sadakane

    2015 IEEE 42ND PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC)    2015年

     概要を見る

    Recently, for the purpose of utilizing renewable energy in a community, interactive electricity power networks, such as smart grid, have received much attention. In those electricity power networks, the technologies for maintain the balance of electricity demand and supply in a limited area become more important. Installing photovoltaic system can be effective for supplying electricity in a limited area at the peak load time, but PV output depends on weather conditions. Thus we propose to combine PV power generation with demand response program. We simulate interchange PV power with demand response program in a residential community. Some numerical results, which demonstrate the validity of the proposed method, will be presented.

    DOI

  • Improvement of Prediction Interval Estimation Algorithm with Just-In-Time Modeling for PV System Operation

    Tomohide Yamazaki, Shinji Wakao, Yu Fujimoto, Yasuhiro Hayashi

    2015 IEEE 42ND PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC)    2015年

     概要を見る

    Output of the photovoltaic (PV) system drastically fluctuates depending on weather conditions. Therefore users of PV systems should manage their energy usage with forecast information of the PV output. Due to the reasons above, we have developed an estimation method of X% prediction interval of solar irradiance. We have achieved a high-accuracy prediction interval for any prediction coefficient X%. However, we found that there are some errors in a case where the prediction coefficient is high. In this paper, we improve the estimation algorithm of the prediction interval.

    DOI

  • Distribution Automation System for Service Restoration Involving Simultaneous Disconnection and Reconnection of Distributed Generators

    Shunsuke Kawano, Yu Fujimoto, Shinji Wakao, Yasuhiro Hayashi, Hideaki Takenaka, Hitoshi Irie, Takashi Y. Nakajima

    2015 IEEE EINDHOVEN POWERTECH    2015年

     概要を見る

    This paper presents a distribution automation system (DAS) for service restoration in the distribution network with photovoltaic (PV) generator systems, which are disconnected simultaneously after a fault and subsequently reconnected after service restoration. Because the reverse power flow of PVs affects voltage in the distribution system, voltage dips and surges occur during the service restoration. However, current DAS do not control voltage regulators such as an on-load tap changer (OLTC) and step voltage regulators (SVRs) during the service restoration. The proposed DAS estimates the voltage in a distribution network considering the simultaneous disconnection of PVs by performing power flow calculations, and it controls the tap position of OLTC and/or SVRs according to the predicted voltage deviation. The voltage after the disconnection of PVs is calculated by estimating the PV output utilizing square kilometer solar radiation data calculated using satellite image data in real time.

    DOI

  • 研究グループ紹介:早稲田大学 先進理工学部 電気・情報生命工学科コンピュータ援用電磁工学研究室

    若尾 真治

    電気学会論文誌. B   135 ( 4 ) NL4_2 - NL4_2  2015年

    CiNii

  • Improvement of Unified Boundary Integral Equation Method in Magnetostatic Shielding Analysis

    Kazuhisa Ishibashi, Takuya Yoshioka, Shinji Wakao, Yasuhito Takahashi, Zoran Andjelic, Koji Fujiwara

    IEEE TRANSACTIONS ON MAGNETICS   50 ( 2 )  2014年02月

     概要を見る

    When using the indirect method in magnetostatic analysis, the magnetic material is represented by the double-layer charge on the material surface. The double-layer charge offers an integral form of scalar potential to give a boundary integral equation (BIE). A unified integral form of excitation potential has been derived, resulting in a BIE capable of solving generic problems. When we apply the standard BIE to analyze magnetic shields by thin shells with high permeability, we usually cannot get accurate results in the shielded space. To accurately solve shielding problems using rough meshes, in this paper we propose a new modeling approach by using a concept of the boundary element method.

    DOI

  • Topology Optimization of Rotor Core Combined With Identification of Current Phase Angle in IPM Motor Using Multistep Genetic Algorithm

    Yoshifumi Okamoto, Yusuke Tominaga, Shinji Wakao, Shuji Sato

    IEEE TRANSACTIONS ON MAGNETICS   50 ( 2 )  2014年02月

     概要を見る

    This paper derives an effective shape of the flux barrier in an interior permanent magnet (IPM) motor. IPM motors generally have many design parameters such as the current phase angle, shape of the rotor and stator's iron core, and shape and position of the magnet. The flux barrier plays an important role in controlling torque characteristics. We apply topology optimization (TO) to the rotor core using a multistep genetic algorithm to determine an effective flux barrier. Furthermore, we extend the TO to combinatorial optimization for considering its effect on the current phase angle. Thus, a reasonable flux barrier with an optimal phase angle is determined.

    DOI

  • Improvements in Material-Density-Based Topology Optimization for 3-D Magnetic Circuit Design by FEM and Sequential Linear Programming Method

    Yoshifumi Okamoto, Yusuke Tominaga, Shinji Wakao, Shuji Sato

    IEEE TRANSACTIONS ON MAGNETICS   50 ( 2 )  2014年02月

     概要を見る

    Topology optimization (TO) makes it possible to obtain new structures for electrical machines. The sensitivity-based method, which can cope with some constraint conditions, is suitable for large-scale three-dimensional TO. However, if the material density is defined by unknown variables in TO, elements with intermediate density (grayscale) occasionally appear. The grayscale cannot clearly show the material allocation within its finite element. Thus, we propose a sigmoid-based filtering function to suppress the generation of grayscale. Moreover, because the constraint condition can be simply taken into consideration, sequential linear programming is occasionally utilized as a topology optimizer. However, the convergence characteristics frequently oscillate and are strongly dependent on the move limit that controls the maximum intensity of the correction vector. To overcome this numerical difficulty, we propose an identification technique for the determination of a quasi-optimal move limit (QOML). This paper demonstrates the performance of both the mathematical function filtering grayscale and QOML.

    DOI

  • Eddy-Current Analysis of Large-Scale Constructions in Railway System by Infinite Edge Elements

    Shogo Yasukawa, Yoshihiro Tawada, Takuya Yoshioka, Shinji Wakao, Tamio Okutani

    IEEE TRANSACTIONS ON MAGNETICS   50 ( 2 )  2014年02月

     概要を見る

    This paper deals with a large-scale eddy-current analysis of the constructions in railway system from the view point of electromagnetic noise assessment. To reduce computational costs with the calculation accuracy kept, we develop some numerical methods and demonstrate their effectiveness using a practical large-scale model.

    DOI

  • Topology design method of flux barrier in IPM motor by means of genetic algorithm implemented by multistep procedure

    Yoshifumi Okamoto, Yusuke Tominaga, Shinji Wakao, Shuji Sato

    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS   46 ( 2 ) 381 - 387  2014年

     概要を見る

    This study derives a high performance flux barrier for an interior permanent magnet (IPM) motor using binary-based topology optimization (TO). TO has a higher degree of optimization than size or shape optimization. An IPM motor has many design parameters including the current phase angle, core shape of rotor and stator, and magnet position and shape. The flux barrier in an IPM motor plays a particularly important role, influencing several characteristics. We apply TO, using a multistep genetic algorithm, to the rotor core in order to determine a flux barrier with the highest torque performance.

    DOI

  • Topology optimization of magnetostatic shielding using multistep evolutionary algorithms with additional searches in a restricted design space

    Yoshifumi Okamoto, Yusuke Tominaga, Shinji Wakao, Shuji Sato

    COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING   33 ( 3 ) 894 - 913  2014年

     概要を見る

    Purpose - The purpose of this paper is to improve the multistep algorithm using evolutionary algorithm (EA) for the topology optimization of magnetostatic shielding, and the paper reveals the effectiveness of methodology by comparison with conventional optimization method. Furthermore, the design target is to obtain the novel shape of magnetostatic shielding.
    Design/methodology/approach - The EAs based on random search allow engineers to define general-purpose objects with various constraint conditions; however, many iterations are required in the FEA for the evaluation of the objective function, and it is difficult to realize a practical solution without island and void distribution. Then, the authors proposed the multistep algorithm with design space restriction, and improved the multistep algorithm in order to get better solution than the previous one.
    Findings - The variant model of optimized topology derived from improved multistep algorithm is defined to clarify the effectiveness of the optimized topology. The upper curvature of the inner shielding contributed to the reduction of magnetic flux density in the target domain.
    Research limitations/implications - Because the converged topology has many pixel element unevenness, the special smoother to remove the unevenness will play an important role for the realization of practical magnetostatic shielding.
    Practical implications - The optimized topology will give us useful detailed structure of magnetostatic shielding.
    Originality/value - First, while the conventional algorithm could not find the reasonable shape, the improved multistep optimization can capture the reasonable shape. Second, An additional search is attached to the multistep optimization procedure. It is shown that the performance of improved multistep algorithm is better than that of conventional algorithm.

    DOI

  • Two-step topology optimization using topology constraint for improving the diversity of solution

    Yu Matsubayashi, Takumi Nagano, Shinji Wakao, Yoshifumi Okamoto

    IEEJ Transactions on Power and Energy   134 ( 8 ) 716 - 723  2014年

     概要を見る

    The topology optimizations which optimize a material arrangement on an element, without extracting feature quantity, are attractive methods, because we can obtain a free idea of the initial design of magnetic devices. However, in actual design processes, all of the required features of the products cannot be included objective functions, such as ease of manufacture or influence of rise in heat. Moreover, the multiple-purpose optimizations concerning many kinds of physical phenomena have difficulty with calculation time. Thus, it is necessary to estimate whether the obtained optimal solution under the limited condition is applicable to an actual designing of magnetic devices. This paper introduces two-step topology optimization method using the constraints on the similarity of the topology, which provides us various topologies including suboptimal solutions. By using the proposed method, we can determine some actual applicable solutions out of obtained solutions. The proposed method was verified by applying it to the C-core problem and the magnetic shield problem, which demonstrated the effectiveness of the proposed method.

    DOI

  • A fundamental study of spectrum center estimation of solar spectral irradiation by statistical pattern recognition

    Aya Iijima, Kazumi Suzuki, Shinji Wakao, Norihiro Kawasaki, Akira Usami

    ELECTRICAL ENGINEERING IN JAPAN   184 ( 1 ) 10 - 18  2013年07月

     概要を見る

    Against a background of environmental problems and energy issues, it is expected that PV systems will be introduced rapidly and connected with power grids on a large scale in the future. For this reason, concerns about how PV power generation will affect supply and demand adjustment in electric power in the future arise, and the technique of correctly grasping PV power generation becomes increasingly important. PV power generation depends on solar irradiance, module temperature, and solar spectral irradiance. Solar spectral irradiance is the distribution of the light intensity for every wavelength. As the spectral sensitivity of solar cells depends on the kind of solar cell, it becomes important for an exact grasp of PV power generation. But the preparation of solar spectral irradiance data is not easy because observational instruments for solar spectral irradiance are expensive. Against this background, in this paper, we propose a new method based on statistical pattern recognition for estimating the spectrum center, which is a representative index of solar spectral irradiance. Some numerical examples obtained by the proposed method are also presented. (c) 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(1): 1018, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22393

    DOI

  • Magnetic Field Analysis in Far-Field Region by Infinite Edge Element With Boundary Surface Integration

    T. Yoshioka, Y. Tawada, K. Tsuzaki, S. Wakao, A. Kameari, T. Tokumasu, Y. Takahashi, H. Igarashi, K. Fujiwara

    IEEE TRANSACTIONS ON MAGNETICS   49 ( 5 ) 1681 - 1684  2013年05月

     概要を見る

    The electromagnetic phenomena intrinsically spread over the infinite space. Thus, the efficient handling of the open boundary is one of the main issues in the electromagnetic field computation. This paper proposes the infinite edge element method (IEEM) with the boundary surface integration to accurately obtain the magnetic field, i.e., the derivatives of vector potentials, in the far-field region.

    DOI

  • Forecasting of Solar Irradiance with Just-In-Time Modeling

    Takanobu Suzuki, Yusuke Goto, Takahiro Terazono, Shinji Wakao, Takashi Oozeki

    ELECTRICAL ENGINEERING IN JAPAN   182 ( 4 ) 19 - 28  2013年03月

     概要を見る

    PV power output mainly depends on solar irradiance, which is affected by various meteorological factors. Thus, it is required to predict solar irradiance in the future for the efficient operation of PV systems. In this paper we develop a novel approach for solar irradiance forecasting, in which we combine the black-box model (JIT modeling) with the physical model (GPV data). We investigate the predictive accuracy of solar irradiance over a wide controlled area of each electric power company by utilizing measured data from 44 observation points throughout Japan provided by JMA and 64 points around Kanto provided by NEDO. Finally, we propose an applied forecasting method of solar irradiance to deal with difficulties in compiling databases. We also consider the influence of different GPV default times on solar irradiance prediction. (C) 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(4): 19-28, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22338

    DOI

  • A versatile clustering method for electricity consumption pattern analysis in households

    Hideitsu Hino, Haoyang Shen, Noboru Murata, Shinji Wakao, Yasuhiro Hayashi

    IEEE Transactions on Smart Grid   4 ( 2 ) 1048 - 1057  2013年

     概要を見る

    Analysis and modeling of electric energy demand is indispensable for power planning, operation, facility investment, and urban planning. Because of recent development of renewable energy generation systems oriented for households, there is also a great demand for analysing the electricity usage and optimizing the way to install electricity generation systems for each household. In this study, employing statistical techniques, a method to model daily consumption patterns in households and a method to extract a small number of their typical patterns are presented. The electricity consumption patterns in a household is modeled by a mixture of Gaussian distributions. Then, using the symmetrized generalized Kullback-Leibler divergence as a distance measure of the distributions, typical patterns of the consumption are extracted by means of hierarchical clustering. The statistical modeling of daily consumption patterns allows us to capture essential similarities of the patterns. By experiments using a large-scale dataset including about 500 houses' consumption records in a suburban area in Japan, it is shown that the proposed method is able to extract typical consumption patterns. © 2010-2012 IEEE.

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  • Computational accuracy enhancement in magnetic field analysis by using orthogonalized infinite edge element method

    Kenta Tsuzaki, Yoshihiro Tawada, Shinji Wakao, Akihisa Kameari, Tadashi Tokumasu, Yasuhito Takahashi, Hajime Igarashi, Koji Fujiwara, Yoshiyuki Ishihara

    IEEJ Transactions on Power and Energy   133 ( 5 ) 8 - 472  2013年

     概要を見る

    The electromagnetic phenomena intrinsically spread over the infinite region. Thus, the efficient handling of open boundary is one of the main issues in the electromagnetic field computations. This paper deals with the orthogonalized infinite edge element method which efficiently performs precise analysis of the infinite region. In this method, there are several parameters to achieve its high accuracy. As one of the parameters, we focus on the reference point and investigate the effect of its position setting on the accuracy. Furthermore, we also evaluate the accuracy of the calculated magnetic field at distance region. By applying boundary element method (BEM) as post-processing, it is found that the high computational accuracy in the region can be effectively achieved. © 2013 The Institute of Electrical Engineers of Japan.

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  • Binary-based topology optimization of magnetostatic shielding by a hybrid evolutionary algorithm combining genetic algorithm and extended compact genetic algorithm

    Yusuke Tominaga, Yoshifumi Okamoto, Shinji Wakao, Shuji Sato

    IEEE Transactions on Magnetics   49 ( 5 ) 2093 - 2096  2013年

     概要を見る

    Topology optimization using the binary information of magnetic material is one of the most attractive simulations for the conceptual design of electrical machines. Heuristic algorithms based on random search allow engineers to define general-purpose objects with various constraint conditions. However, it is difficult for topology optimization to realize a practical solution without island and void distribution. In this paper, we propose a hybrid evolutionary algorithm that is composed of a genetic algorithm (GA) and extended compact GA (ECGA). We verify the effectiveness of the proposed algorithm on the binary topology optimization problem for the design of magnetostatic shielding. © 1965-2012 IEEE.

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  • Time-domain parallel finite-element method for fast magnetic field analysis of induction motors

    Yasuhito Takahashi, Tadashi Tokumasu, Masafumi Fujita, Takeshi Iwashita, Hiroshi Nakashima, Shinji Wakao, Koji Fujiwara

    IEEE Transactions on Magnetics   49 ( 5 ) 2413 - 2416  2013年

     概要を見る

    This paper investigates the effectiveness of the time domain parallelization in magnetic field analyses of practical electric machines. We propose an efficient procedure to parallelize transient as well as steady-state analyses by generalizing the formulation of the parallel time-periodic finite element method. The proposed method is called the time domain parallel finite element method (TDPFEM) because it can be applied to both transient and steady-state analyses. Additionally, we derive a special condition of the slip to reduce computational costs for steady-state analyses of induction motors by using a half-cycle polyphase time-periodic condition. © 1965-2012 IEEE.

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  • Nonlinear magnetostatic analysis by unified BIE utilizing potential gap due to loop currents

    Kazuhisa Ishibashi, Zoran Andjelic, Yasuhito Takahashi, Yoshihiro Tawada, Takuya Yoshioka, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE Transactions on Magnetics   49 ( 5 ) 1573 - 1576  2013年

     概要を見る

    Since the line loop current is equivalent to the double layer charge, it gives an integral form of scalar potential. The segmental loop current on the interface between magnetic materials produces a potential gap, which works to give a boundary integral equation (BIE). By virtue of another potential gap due to a fictitious circulating current along the contour of cut-surface in the material, the excitation potential becomes single valued and the BIE becomes applicable to generic problems without any restriction. Regarding the nonlinear magnetic material as composed of segmental materials with different values of permeability, we get the same BIE for the nonlinear analysis as for the linear analysis. In order to check the adequacy and effectiveness of the nonlinear BIE, we solve a typical magnetostatic problem and compare the computed results with those by the conventional magnetic moment method. © 1965-2012 IEEE.

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  • Error effect of PV output and load power forecast on operation design of PV system with storage battery

    Takayoshi Hayashi, Takahiro Shimoo, Shinji Wakao

    IEEJ Transactions on Power and Energy   133 ( 11 ) 903 - 909  2013年

     概要を見る

    In the past, we have proposed some battery operations in a photovoltaic (PV) system using the PV output and load power forecasts. In the proposed method, we utilized multi-objective optimization for a residential area model that includes a large number of PV systems with storage batteries. To practically demonstrate that the proposed operation effectively improves the economic and environmental efficiencies, it is indispensable to evaluate the forecast error effects on operation design of PV system with storage battery. In this paper, we propose a method for evaluating the robustness of battery operation taking account of the statistical characteristics of forecast errors. Some numerical examples, which show the validity of the proposed method, are also presented. © 2013 The Institute of Electrical Engineers of Japan.

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  • Control Method for Harmonic Voltage Injection to Achieve Noise Reduction in Position-Sensorless Control of Permanent-Magnet Synchronous Motors at Low Speeds

    Shun Taniguchi, Toshihiro Homma, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    ELECTRICAL ENGINEERING IN JAPAN   179 ( 3 ) 49 - 56  2012年05月

     概要を見る

    In this study, we examine the relationship between harmonic voltage injection, acoustic noise, and position estimation performance in a PMSM when a position-sensorless control method involving harmonic voltage injection is used at low speeds. Further, we propose a novel control method for voltage injection; this method can be used to reduce acoustic noise in the motor. The proposed control method is verified by performing numerical simulations and carrying out experiments using a four-pole, 2-kW, 2100-rpm IPMSM (interior permanent-magnet synchronous motor). (c) 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(3): 4956, 2012; Published online in Wiley Online Library (). DOI 10.1002/eej.21246

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  • Comparison Between Fast Steady-State Analysis Methods for Time-Periodic Nonlinear Magnetic Field Problems

    Yasuhito Takahashi, Tadashi Tokumasu, Masafumi Fujita, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   48 ( 2 ) 235 - 238  2012年02月

     概要を見る

    This paper investigates the effectiveness of various methods to accelerate the convergence to a steady state in time-periodic electromagnetic field problems. We first introduce the time-periodic explicit error correction (TP-EEC) method taking account of both the dc and linearly-varying error components and propose the harmonics TP-EEC method which enables us to achieve the increase in error correction frequency. Then, we discuss the convergence property of the TP-EEC methods based on the error analysis. The advantages and disadvantages of the TP-EEC method and the time differential correction (TDC) method are investigated from the viewpoints of computational costs and application scope.

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  • Magnetic Field Evaluation at Vertex by Boundary Integral Equation Derived From Scalar Potential of Double Layer Charge

    K. Ishibashi, Z. Andjelic, Y. Takahashi, T. Takamatsu, T. Fukuzumi, S. Wakao, K. Fujiwara, Y. Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   48 ( 2 ) 459 - 462  2012年02月

     概要を見る

    Adopting the integral representation of scalar potential due to double layer charge, we derive a boundary integral equation with one unknown to solve magnetostatic problems. The double layer charge produces a potential gap at the air-material boundary without disturbing the continuity of normal magnetic flux density and the potential gap makes the tangential component of magnetic field continuous; accordingly, the boundary conditions are fully fulfilled even with one unknown. The boundary integral equation is capable of solving the double layer charge at edges and corners. Once the double layer charge is solved, it gives directly the magnetic flux density by Biot-Savart law. In this paper, we investigate how to evaluate the magnetic flux density at the vertex.

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  • Some Treatments of Fictitious Volume Charges in Nonlinear Magnetostatic Analysis by BIE

    K. Ishibashi, Z. Andjelic, Y. Takahashi, T. Takamatsu, K. Tsuzaki, S. Wakao, K. Fujiwara, Y. Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   48 ( 2 ) 463 - 466  2012年02月

     概要を見る

    The scalar potential formulation by the boundary integral equation approach is attractive for numerical analysis but has fatal drawbacks due to a multi-valued function in current excitation. We derive an all-purpose boundary integral equation with double layer charges as the state variable and apply it to nonlinear magnetostatic problems by regarding the nonlinear magnetization as fictitious volume charges. We investigate two approaches how to treat the fictitious charges. In discretization by the constant volume element, a surface loop current is introduced for the volume charge. By the linear volume element, the fictitious charges are evaluated on the condition that the divergence of the magnetic flux density is zero. We give a comparative study of these two approaches.

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  • Parallel Time-Periodic Finite-Element Method for Steady-State Analysis of Rotating Machines

    Yasuhito Takahashi, Takeshi Iwashita, Hiroshi Nakashima, Tadashi Tokumasu, Masafumi Fujita, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   48 ( 2 ) 1019 - 1022  2012年02月

     概要を見る

    This paper investigates the parallelization of the time-periodic finite-element method in nonlinear magnetic field analyses of rotating machines. The developed method, which can obtain the steady state solutions directly, provides large granularity even in the small-scale problems compared with the ordinary parallel FEM based on the domain decomposition approach. Furthermore, we apply the parallel TPFEM to analyses of induction motors which have different time periodicities in stator and rotor regions due to the slip. Numerical results verify the effectiveness of the developed method.

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  • Orthogonalized Infinite Edge Element Method-Convergence Improvement by Orthogonalization of Hilbert Matrix in Infinite Edge Element Method

    S. Tamitani, K. Tsuzaki, Shinji Wakao, T. Tokumasu, Y. Takahashi, A. Kameari, H. Igarashi, K. Fujiwara, Y. Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   48 ( 2 ) 363 - 366  2012年02月

     概要を見る

    This paper proposes an orthogonalization of the Hilbert matrix in element matrices of the infinite edge elements. The validity of the infinite edge element is demonstrated in previous researches, but the Hilbert matrix results in extremely slow convergence in the ICCG method, especially when using higher order expansions. The proposed orthogonalization technique improves the convergence drastically and it makes the infinite elements practical in the electromagnetic FEM analysis of the open boundary problems in quasi-static magnetic fields.

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  • A fundamental study on spectrum center estimation of solar spectral irradiation by the statistical pattern recognition

    Aya Iijima, Kazumi Suzuki, Shinji Wakao, Norihiro Kawasaki, Akira Usami

    IEEJ Transactions on Power and Energy   132 ( 2 ) 189 - 196  2012年

     概要を見る

    With a background of environmental problems and energy issues, it is expected that PV systems will be introduced rapidly and connected with power grids on a large scale in the future. For this reason, the concern to which PV power generation will affect supply and demand adjustment in electric power in the future arises and the technique of correctly grasping the PV power generation becomes increasingly important. The PV power generation depends on solar irradiance, temperature of a module and solar spectral irradiance. Solar spectral irradiance is distribution of the strength of the light for every wavelength. As the spectrum sensitivity of solar cell depends on kind of solar cell, it becomes important for exact grasp of PV power generation. Especially the preparation of solar spectral irradiance is, however, not easy because the observational instrument of solar spectral irradiance is expensive. With this background, in this paper, we propose a new method based on statistical pattern recognition for estimating the spectrum center which is representative index of solar spectral irradiance. Some numerical examples obtained by the proposed method are also presented. © 2012 The Institute of Electrical Engineers of Japan.

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  • Magnetostatic analysis by BEM with magnetic double layer as unknown utilizing volume magnetic charge

    Kazuhisa Ishibashi, Zoran Andjelic, Yasuhito Takahashi, Tomoaki Takamatsu, Kenta Tsuzaki, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS   39 ( 1-4 ) 711 - 717  2012年

     概要を見る

    The volume integral equation approach replaces magnetic materials with the magnetization in magnetostatic analysis. The concept of magnetic shell relates the magnetization with loop currents. The loop current is equivalent to the magnetic double layer, which gives an integral form of the scalar potential. The nonlinear magnetic field is formulated by regarding the nonlinear magnetization as volume magnetic charges. This paper presents how to utilize the volume charge to solve nonlinear problems. In the case of constant volume element we replace the volume charges with the surface loop currents to derive the nonlinear boundary integral equations having the line and surface loop currents as unknowns. The boundary integral equation is solved iteratively while improving alternately the loop and surface currents.

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  • Automatic Extraction of Basic Electricity Consumption Patterns in Household

    Haoyang Shen, Hideitsu Hino, Noboru Murata, Shinji Wakao, Yasuhiro Hayashi

    INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA)    2012年

     概要を見る

    Electricity consumption in households varies dependent on a lot of possible reasons such as lifestyle, family configuration, and weather. It is of great importance to optimize the electricity generation system to install for each household. In our previous work, we proposed a clustering approach for extracting a small number of basic electricity consumption patterns in a household. In this study, we apply the method to a larger dataset with many households. In the previous work, we determined the number of basic patterns in a heuristic manner. In this work, we use gap statistics to automatically determine an appropriate number of basic patterns, and we obtained a reasonable result on a large-scale data.

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  • Micromagnetic Simulations of Perpendicular Recording Head Using the Parallel Fast Multipole Method Specialized for Uniform Brick Elements

    Yasuhito Takahashi, Takeshi Iwashita, Hiroshi Nakashima, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   47 ( 10 ) 3805 - 3808  2011年10月

     概要を見る

    This paper develops a parallel fast multipole method specialized for uniform brick elements to achieve large-scale micromagnetic simulations of a practical perpendicular recording head within acceptable computation time. In highly parallel computation, it is indispensable to equally distribute the computing load among processes so as to obtain the good parallel speedup. The load balancing technique which can be regarded as the domain decomposition method based on octree structure in the fast multipole method is discussed. The scalability of the parallel fast multipole accelerated micromagnetic simulation is investigated with 100 or more MPI processes.

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  • A Study of Mesh Deformation Methods for Magnetic Field Analysis

    Masahiko Miwa, Koji Tani, Takashi Yamada, Shinji Wakao

    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING   6 ( 5 ) 497 - 502  2011年09月

     概要を見る

    In this paper, we describe a study of mesh deformation methods for magnetic field analysis. We propose an efficient method that is a combination of two conventional mesh deformation methods. We numerically estimate the basic performance of the proposed method and conventional methods using three-dimensional mesh models for magnetic field analysis. We highlight the advantages of the proposed method with respect to its robustness and computational cost. (C) 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons,

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  • Finite-Element Analysis of Magnetic Field Problem With Open Boundary Using Infinite Edge Element

    Satoshi Tamitani, Tomoaki Takamatsu, Asuka Otake, Shinji Wakao, Akihisa Kameari, Yasuhito Takahashi

    IEEE TRANSACTIONS ON MAGNETICS   47 ( 5 ) 1194 - 1197  2011年05月

     概要を見る

    This paper proposes a novel effective method for open boundary problems by using the finite-element method (FEM) with a new formulation of the infinite edge element. We developed the formulation of the infinite element by adopting the characteristic of conventional edge elements, resulting in a sparse and symmetric matrix. This proposed technique with the infinite edge element has the advantage of drastically reducing the computational burden with keeping the analyses' accuracy. Some numerical examples which demonstrate the validity of the proposed method are presented.

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  • Convergence Acceleration in Steady State Analysis of Synchronous Machines Using Time-Periodic Explicit Error Correction Method

    Yasuhito Takahashi, Hiroyuki Kaimori, Akihisa Kameari, Tadashi Tokumasu, Masafumi Fujita, Shinji Wakao, Takeshi Iwashita, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   47 ( 5 ) 1422 - 1425  2011年05月

     概要を見る

    This paper develops the time-periodic explicit error correction (TP-EEC) method for the convergence acceleration to a steady state in transient analysis of synchronous machines. The methods to deal with the movement of the rotor and different time-periodicity in the fixed and moving parts of the mesh are investigated. Furthermore, we propose the novel TP-EEC method based on the polyphase time periodic condition. Numerical results verify the effectiveness of the developed methods.

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  • Performance Evaluation of a Parallel Fast Multipole Accelerated Boundary Integral Equation Method in Electrostatic Field Analysis

    Yasuhito Takahashi, Takeshi Iwashita, Hiroshi Nakashima, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    IEEE TRANSACTIONS ON MAGNETICS   47 ( 5 ) 1174 - 1177  2011年05月

     概要を見る

    This paper investigates the scalability of a parallel fast multipole accelerated boundary integral equation method in electrostatic field analyses. A load balancing technique suitable for highly parallel computation with 100 or more processes, which is a domain decomposition method based on octree structure in the FMM, is also proposed. Numerical results clarify the effectiveness of the developed method in practical models with complicated geometry.

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  • Large-scale analysis of magnetic particle dynamics taking into account contact force and magnetic interaction with the fast multipole method

    Takuya Tatsuishi, Yasuhito Takahashi, Masahiko Miwa, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    JOURNAL OF APPLIED PHYSICS   109 ( 7 )  2011年04月

     概要を見る

    This paper investigates a large-scale analysis of magnetic particles&apos; behavior in magnetic fields by using a novel method combining the discrete element method and the magnetic interaction calculation with the fast multipole method (FMM). Furthermore, the effective formulae for the derivative of the magnetic field in the FMM procedure, which is necessary to calculate magnetic forces among a large number of magnetic particles, are proposed. Numerical examples of large-scale magnetic-particle chain analysis that demonstrate the effectiveness of the proposed method are presented. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3556914]

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  • Multi-objective optimization of storage battery operation in clustered residential grid-interconnected PV

    Shinji Wakao, Shingo Kinoshita, Takahiro Shimoo, Yusuke Miyamoto

    17th Power Systems Computation Conference, PSCC 2011    2011年01月

     概要を見る

    In the near future, photovoltaic (PV) power generation systems will become widespread. In this study, we apply multi-objective optimization to the designed model: the concentrated introduction of PV systems with stationary batteries and electric vehicle (EV) batteries in housing areas to fulfill the diverse demands from various sectors, including electrical power companies and utility customers. In the computations, we propose a novel method for modeling the residential load and PV output power based on the measured data from a national research project in Japan. Furthermore, we carry out data mining of the optimization results using a self-organizing map as an effective analysis tool for the design of PV systems with storage batteries.

  • Forecast method of solar irradiance with just-in-time modeling

    Takanobu Suzuki, Yusuke Goto, Takahiro Terazono, Shinji Wakao, Takashi Oozeki

    IEEJ Transactions on Power and Energy   131 ( 11 ) 5 - 919  2011年

     概要を見る

    PV power output mainly depends on the solar irradiance which is affected by various meteorological factors. So, it is required to predict solar irradiance in the future for the efficient operation of PV systems. In this paper, we develop a novel approach for solar irradiance forecast, in which we introduce to combine the black-box model (JIT Modeling) with the physical model (GPV data). We investigate the predictive accuracy of solar irradiance over wide controlledarea of each electric power company by utilizing the measured data on the 44 observation points throughout Japan offered by JMA and the 64 points around Kanto by NEDO. Finally, we propose the application forecast method of solar irradiance to the point which is difficulty in compiling the database. And we consider the influence of different GPV default time on solar irradiance prediction. © 2011 The Institute of Electrical Engineers of Japan.

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  • A measure of credibility of solar power prediction

    Haoyang Shen, Hideitsu Hino, Noboru Murata, Shinji Wakao

    Proceedings - 10th International Conference on Machine Learning and Applications, ICMLA 2011   2   286 - 291  2011年

     概要を見る

    Recently, remarkable developments of new energy technologies have been achieved against various energy problems. Photovoltaic (PV) system, one of such technologies, has an advantage of utilizing infinite and clean energy. On the contrary, it also has a disadvantage of unreliable power supply mainly caused by unstable weather. The fluctuation of the power supply of PV systems are considerably large because of rapid insulation changes and rapid weather changes, and in some cases, it seems impossible to realize high-accuracy prediction even with sophisticated prediction models. In this paper, using recently proposed estimator for the Shannon information content, a method to output a measure of credibility for prediction is proposed. With the proposed method, it is possible to judge whether the energy supply at a certain future time is unpredictably fluctuate compared to the current value or not, and it is possible to take measures against the rapid change of solar energy generation in advance. From an experimental result using solar energy supply data, we see that the proposed measure of credibility reflects the difficulty of predicting solar energy supply. © 2011 IEEE.

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  • Optimization of installation and operation for retail store with photovoltaic, storage battery and EV quick charger

    Jun Yamasaki, Ryuichiro Tominaga, Yohei Ishii, Atsushi Shimizu, Shingo Kinoshita, Shinji Wakao

    Conference Record of the IEEE Photovoltaic Specialists Conference     001893 - 001896  2011年

     概要を見る

    In the near future, it is expected the widespread use of electric vehicles (EVs). And a lot of retail stores will have EV quick chargers. This might cause a problem that is a rise in electricity costs of the stores because of an increase in maximum load power. The stores want to reduce electricity cost especially related with load peak for low cost operation. Installation of photovoltaic (PV) and storage battery system are one of the solutions for peak cutting. So it is important to decide the reasonable system scale to install. On the other hand, the stores also want to make battery lifetime longer for low cost operation. Thus, an optimization method of system installation and operation for a retail store is discussed in this paper. In the first step, the system scale is optimized, whose purpose is maximizing the effect of peak cut with minimum installation cost. In the optimization, a genetic algorithm (GA) is employed to solve the multi-objective trade-off problem. In the next step, system operation is optimized to make battery lifetime longer. In order to extend the battery lifetime, start timing control of the EV quick charge is effective. However, start timing control delays the beginning of charging, which makes it unattractive for customers. The relationship between delay time and battery lifetime improvement is investigated. And a design method to achieve long system lifetime is shown. © 2011 IEEE.

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  • Operation design of PV system with storage battery by using next-day residential load forecast

    Yusuke Goto, Takanobu Suzuki, Takahiro Shimoo, Takayoshi Hayashi, Shinji Wakao

    Conference Record of the IEEE Photovoltaic Specialists Conference     002369 - 002374  2011年

     概要を見る

    Recently, many people in the world pay attention to the renewable energy and a photovoltaic system becomes especially worthy for the future of the earth. In this paper, we investigate the operation of PV system with storage battery by using next-day residential load forecast. First, we propose the application of a simple and high-precision modeling method, i.e., Just-In-Time Modeling to the forecast of residential load. And we carry out the improvement in predictive accuracy by the input selection and the weighting method. Next, we simulate the operation of PV system with storage battery by using the load forecast information. The result shows that the introduction of load forecast into PV system operation contributes to environmental conservation and reduction of operating cost. © 2011 IEEE.

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  • Operetion design of hybrid PV and fuel cell system with storage battery

    Ryo Nakayama, Shinji Wakao

    Conference Record of the IEEE Photovoltaic Specialists Conference     002397 - 002401  2011年

     概要を見る

    Recently, photovoltaic (PV) system has attracted attention because of serious environmental and energy problems. However, if PV systems are intensively connected to the grid in a specific area, it is predicted that the voltage of the distribution feeder in power system increases due to the reversal power flow. Such degradation of electric power quality leads to the depression of PV output by power conditioners. In our previous research, we have overcome the problem by introducing the storage batteries and optimally charging and discharging them [1][2]. On the other hand, the residential fuel cell (FC) system has been a focus of attention because FC has achieved a primary energy efficiency of 80% by making the best use of generator waste heat. When the FC system is operated according to the residential thermal demand as a general operation, its electric output doesn't always follow the residential electric load. Therefore, it is also indispensable to introduce the storage battery to the hybrid system with a combination of PV subject to weather condition and FC giving the priority to heat supply. In this paper, we investigate the optimal operation of the storage battery for the hybrid PV and FC system. © 2011 IEEE.

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  • Extraction of basic patterns of household energy consumption

    Haoyang Shen, Hideitsu Hino, Noboru Murata, Shinji Wakao

    Proceedings - 10th International Conference on Machine Learning and Applications, ICMLA 2011   2   275 - 280  2011年

     概要を見る

    Solar power, wind power, and co-generation (combined heat and power) systems are possible candidate for household power generation. These systems have their advantages and disadvantages. To propose the optimal combination of the power generation systems, the extraction of basic patterns of energy consumption of the house is required. In this study, energy consumption patterns are modeled by mixtures of Gaussian distributions. Then, using the symmetrized Kullback-Leibler divergence as a distance measure of the distributions, the basic pattern of energy consumption is extracted by means of hierarchical clustering. By an experiment using the Annex 42 dataset, it is shown that the proposed method is able to extract typical energy consumption patterns. © 2011 IEEE.

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  • Convergence Acceleration of Time-Periodic Electromagnetic Field Analysis by the Singularity Decomposition-Explicit Error Correction Method

    Yasuhito Takahashi, Tadashi Tokumasu, Akihisa Kameari, Hiroyuki Kaimori, Masafumi Fujita, Takeshi Iwashita, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   46 ( 8 ) 2947 - 2950  2010年08月

     概要を見る

    This paper proposes a novel method for the improvement of the convergence to a steady state in time-periodic transient nonlinear eddy-current analyses. The proposed method, which is based on the time-periodic finite element method and the singularity decomposition-explicit error correction method, can extract poorly converged error components corresponding to the large time constants of an analyzed system. The correction of the extracted error components efficiently accelerates the convergence to a steady state. Numerical results verify the effectiveness of the proposed method.

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  • Design of Railway Wheel Detector Insusceptible to Electromagnetic Noise

    Asuka Otake, Kenta Takayasu, Shinji Wakao, Tamio Okutani, Yasuhito Takahashi, Masahiko Saito, Akihisa Toyoda

    IEEE TRANSACTIONS ON MAGNETICS   46 ( 8 ) 2731 - 2734  2010年08月

     概要を見る

    This paper investigates a mutually reverse (MR) unit coil as a wheel detector, which is more insusceptible to electromagnetic noise than conventional wheel detectors. We carry out the optimal design of the receiving coils for the further accurate detection of the wheel by means of magnetic field computations. Then, we accurately estimate the signaling receive level in spite of efficiently reducing the computational burden by the response surface methodology. Furthermore, we propose the robust design of the receiving coils by considering the degradation of the signaling receive level due to the positioning error.

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  • 直方体要素用高速多重極法を用いた大規模マイクロマグネティックス計算の並列化

    高橋康人, 岩下武史, 中島浩, 若尾真治

    情報処理学会論文誌:コンピューティングシステム   3 ( 1 ) 101 - 111  2010年03月

  • Proposal for a Benchmark Model of a Laminated Iron Core and a Large-Scale and Highly Accurate Magnetic Analysis

    Yasuhito Takahashi, Shinji Wakao, Koji Fujiwara, Hiroyuki Kaimori, Akihisa Kameari

    ELECTRICAL ENGINEERING IN JAPAN   170 ( 1 ) 26 - 35  2010年01月

     概要を見る

    This paper describes a benchmark model proposed for the clarification of the characteristic of various methods for modeling the laminated iron core. In order to obtain a reference solution of the benchmark model, a large-scale nonlinear magnetostatic field analysis with a mesh fine enough to represent the microscopic structure of the laminated iron core is carried out by using the hybrid finite element-boundary element (FE-BE) method combined with the fast multipole method (FMM) based on diagonal forms for translation operators. The computational costs and accuracy of two kinds of homogenization methods are discussed, comparing them with the reference solution. As a consequence, it is verified that the homogenization methods can analyze magnetic fields in laminated iron core within acceptable computational costs. (C) 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 26-35, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20809

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  • Data mining method for battery operation optimization in photovoltaics

    Katsunori Sato, Shinji Wakao

    IEEJ Transactions on Power and Energy   130 ( 3 ) 4 - 319  2010年

     概要を見る

    Recently, a photovoltaic (PV) system has attracted attention because of serious environmental and energy problems. In near future, PV systems intensively connected to the grid will bring about the difficulties in the power system operation. As a countermeasure, this paper deals with the introduction of storage battery for making the unstable PV power controllable. In this regard, when we introduce a storage battery into a PV system, we have to consider the advantages and disadvantages. In order to evaluate the system from various perspectives, we have carried out multi-objective optimization of battery operation in PV system design. However, as the number of objective functions increases, it becomes difficult to appropriately interpret the correlation among objective functions and design variables. With this background, in this paper, a novel computational method is proposed for data mining of PV system design, in which we make an attempt to effectively extract the design information of the battery system with the use of Self-Organizing Map (SOM). © 2010 The Institute of Electrical Engineers of Japan.

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  • Development of distribution network equipment to support the solution of problem of connecting distributed generators (Answer) and verification experiment of active coordinated operation of distributed generator and distribution network

    Shigekazu Sakai, Yasuhiro Hayashi, Shoji Kawasaki, Junya Matsuki, Junpei Baba, Akihiko Yokoyama, Masahide Hojo, Shinji Wakao, Kenjiro Mori, Yoshiaki Fuwa

    IEEJ Transactions on Power and Energy   130 ( 5 ) 1 - 483  2010年

     概要を見る

    Recently, total number of distributed generators (DGs) such as photovoltaic generation system and wind power generation system connected to an actual distribution network increases drastically. The distribution network connected with many distributed generators must be operated keeping reliability of power supply, and power quality. In order to accomplish active distribution network operation to take advantage of many connections of DGs, a new coordinated operation of distribution system with many connections of DGs is necessary. So far, the authors have proposed a coordinated operation of distribution network system connected with many DGs by using sectionalizing switches control method, sending voltage control method, computation method of acceptable maximum output of DG and determination method of optimal smoothing time constant of wind power generation system with storage battery. In this paper, the authors develop an experiment of scaled-down three-phase distribution system with distributed generators in order to check the validity of the proposed approach. © 2010 The Institute of Electrical Engineers of Japan.

    DOI

  • Convergence acceleration in transient analysis of rotating machines using time-periodic explicit error correction method

    Yasuhito Takahashi, Hiroyuki Kaimori, Akihisa Kameari, Tadashi Tokumasu, Masafumi Fujita, Shinji Wakao, Takeshi Iwashita, Koji Fujiwara, Yoshiyuki Ishihara

    Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010    2010年

     概要を見る

    This paper investigates the acceleration of convergence to a steady state in a transient analysis of rotating machines using the time-periodic explicit error correction (TP-EEC) method. The efficient method to deal with the movement of the rotor and different time-periodicity in the fixed and moving parts of the mesh is developed. Numerical results verify the effectiveness of the developed method. © 2010 IEEE.

    DOI

  • Finite element analysis of magnetic field problem with open boundary using infinite element technique

    S. Tamitani, T. Takamatsu, A. Otake, S. Wakao, A. Kameari, Y. Takahashi

    Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010    2010年

     概要を見る

    The electromagnetic phenomena intrinsically spread over the infinite space. Thus, the efficient handling of open boundary is one of the main issues in the electromagnetic field computations. This paper deals with a FE formulation combined with infinite elements as a novel effective method for open boundary problems. Some numerical examples which demonstrate the validity of the proposed method are presented. © 2010 IEEE.

    DOI

  • Multiobjective design optimization of electric machine by using genetic algorithm with aggressive species diversity

    Yusuke Tsurumi, Shinji Wakao

    Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010    2010年

     概要を見る

    In the design optimization of electric machine, there is a strong need to comprehend in detail the tradeoff relationships among the various objective functions. Therefore, it is important to obtain the sufficiently diverse pareto solutions for appropriately designing electric machine. However, the conventional genetic algorithm (GA) doesn't necessarily find out the diverse pareto solutions. In this paper, we propose a GA with new concept of crowding distance which enables us to obtain the sufficiently diverse pareto solution. Some numerical examples which demonstrate the validity of the proposed method is presented. © 2010 IEEE.

    DOI

  • Performance evaluation of parallel fast multipole accelerated boundary integral equation method in electrostatic field analysis

    Yasuhito Takahashi, Takeshi Iwashita, Hiroshi Nakashima, Shinji Wakao, Koji Fujiwara, Yoshiyuki Ishihara

    Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010    2010年

     概要を見る

    This paper investigates the scalability of a parallel fast multipole accelerated boundary integral equation method in electrostatic field analyses. A load balancing technique suitable for highly parallel computation with 100 or more processes is also proposed. Numerical results clarify the effectiveness of the developed method in practical models with complicated geometry. © 2010 IEEE.

    DOI

  • 太陽光発電における蓄電システムの運用最適化情報の抽出方法

    佐藤勝則, 若尾真治

    電気学会論文誌B   130 ( 3 ) 4 - 319  2010年

    DOI

  • 分散型電源連系課題解決支援実験システム(ANSWER)の構築と分散型電源と配電ネットワークとの協調運用形態の実験検証

    酒井重和, 林 泰弘, 川章司, 松木純也, 馬場旬平, 横山明彦, 北條昌秀, 若尾真治, 森 健二郎, 不破由晃

    電気学会論文誌B   130 ( 5 ) 1 - 483  2010年

    DOI

  • Starting Procedure of Rotation Sensorless PMSM at Coasting Condition for Railway Vehicle Traction

    Toshifumi Yamakawa, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama, Shun Taniguchi, Shinsuke Mochizuki

    ELECTRICAL ENGINEERING IN JAPAN   169 ( 2 ) 56 - 63  2009年11月

     概要を見る

    This paper investigates the procedure for starting a rotation sensorless PMSM under coasting condition for railway vehicle traction. To achieve restarting, the initial rotor position and speed at restart are needed. The existing algorithm for estimation of the initial position and speed cannot be applied to railway vehicle traction because of the greater speed range and the longer current sampling time. We propose a novel method for estimation of the initial speed. The estimation method is verified experimentally to assure that it is suitable for application to the railway vehicle traction system. (C) 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(2): 56-63, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20764

    DOI

  • Improvement of convergence characteristic in nonlinear transient eddy-current analyses using the error correction of time integration based on the time-periodic FEM and the EEC method

    Yasuhito Takahashi, Tadashi Tokumasu, Masafumi Fujita, Shinji Wakao, Takeshi Iwashita, Masanori Kanazawa

    IEEJ Transactions on Power and Energy   129  2009年07月

     概要を見る

    This paper proposes novel techniques for the improvement of the convergence characteristic of step-by-step time integrations in nonlinear transient eddy-current analyses. The proposed methods, which are based on the time-periodic finite-element method and the explicit error correction method, can extract poorly-converged error components corresponding to large time constants of an analyzed system. The correction of the extracted error components accelerates the convergence of transient calculation efficiently. Furthermore, we extend the performance of the proposed methods in nonlinear problems. Some numerical results that verify the effectiveness of the proposed methods are also presented. © 2009 The Institute of Electrical Engineers of Japan.

    DOI

  • 時間周期有限要素法とEEC法に基づく非線形過渡電磁場解析における時間積分の収束性改善

    高橋康人, 徳増 正, 藤田真史, 若尾真治, 岩下武史, 金澤正憲

    電気学会論文誌B   129-B ( 6 ) 791 - 798  2009年06月

    DOI

  • Active Coordinated Operation of a Distribution Network System for Many Connections of Distributed Generators

    Yasuhiro Hayashi, Shoji Kawasaki, Junya Matsuki, Shinji Wakao, Junpei Baba, Masahide Hojo, Akihiko Yokoyama, Naoki Kobayashi, Takao Hirai, Kohei Oishi

    ELECTRICAL ENGINEERING IN JAPAN   167 ( 3 ) 46 - 57  2009年05月

     概要を見る

    Recently, the total number of distributed generators (DGs) Such as photovoltaic generation system and wind turbine generation system connected to an actual distribution network has increased drastically. The distribution network connected to many distributed gerators must be operated keeping reliability of power supply, power quality, and loss minimization. In order to accomplish active distribution network operation to take advantage of many connections of DGs, a new coordinated operation of distribution system with many connections of DGs is necessary. In this paper, the authors propose a coordinated operation of distribution network system connected to many DGs by using newly proposed sectionalizing switch control, sending voltage control, and computation of available DG connection capability. In order to check the validity of the proposed coordinated operation of distribution system, numerical simulations using the proposed coordinated distribution system operation are carried out in a practical distribution network model. (C) 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(3): 46-57, 2009; Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/eej.20655

    DOI

  • Micromagnetic simulation by using the fast multipole method specialized for uniform brick elements

    Y. Takahashi, S. Wakao, T. Iwashita, M. Kanazawa

    JOURNAL OF APPLIED PHYSICS   105 ( 7 )  2009年04月

     概要を見る

    This paper describes a large-scale micromagnetic simulation by using the fast multipole method (FMM) specialized for uniform brick elements. The fast Fourier transform (FFT) is widely used to reduce computational costs of the demagnetizing field calculation. However, the FFT still requires operation counts of O(N log N), where N is the number of elements, which results in the huge computational costs in large-scale problems. To overcome the difficulties, we develop an O(N) approach based on the FMM. In a micromagnetic simulation, an analyzed region is usually subdivided into uniform elements. By making the best use of the periodic structure of uniformly distributed elements, the computational costs of the FMM can be reduced drastically. A large-scale micromagnetic simulation of a single-pole-type head demonstrates the effectiveness of the specialized FMM from the viewpoints of calculation time and memory requirements, compared with the FFT. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3068012]

    DOI

  • Micromagnetic simulation by using the fast multipole method specialized for uniform brick elements

    Y. Takahashi, S. Wakao, T. Iwashita, M. Kanazawa

    JOURNAL OF APPLIED PHYSICS   105 ( 7 ) 07D514  2009年04月

     概要を見る

    This paper describes a large-scale micromagnetic simulation by using the fast multipole method (FMM) specialized for uniform brick elements. The fast Fourier transform (FFT) is widely used to reduce computational costs of the demagnetizing field calculation. However, the FFT still requires operation counts of O(N log N), where N is the number of elements, which results in the huge computational costs in large-scale problems. To overcome the difficulties, we develop an O(N) approach based on the FMM. In a micromagnetic simulation, an analyzed region is usually subdivided into uniform elements. By making the best use of the periodic structure of uniformly distributed elements, the computational costs of the FMM can be reduced drastically. A large-scale micromagnetic simulation of a single-pole-type head demonstrates the effectiveness of the specialized FMM from the viewpoints of calculation time and memory requirements, compared with the FFT. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3068012]

    DOI

  • Investigation of Algebraic Multigrid Method for Magnetic Field Analysis of an Electric Machine With a Laminated Core

    Masahiko Miwa, Takashi Yamada, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   45 ( 3 ) 992 - 995  2009年03月

     概要を見る

    In this paper, we describe the applicability of Algebraic Multigrid Method (AMG method) as a fast solution for magnetic field analysis of an electric machine with a laminated core. In an experimental analysis, we have found that there are some cases where the calculation speed can be improved by using the AMG method for a fine mesh that models a laminated iron core exactly. Therefore we investigated the convergence characteristic of the standard Incomplete Cholesky Conjugate Gradient method (standard ICCG method) and the Conjugate Gradient method preconditioned with AMG method (AMGCG method) for the simple and actual analysis models. The numerical results show that the AMGCG method provides fast solutions for laminated mesh models for which the standard ICCG method does not work well in many analysis cases.

    DOI

  • Large-Scale Eddy-Current Analysis of Conductive Frame of Large-Capacity Inverter by Hybrid Finite Element-Boundary Element Method

    Takuya Tatsuishi, Yasuhito Takahashi, Shinji Wakao, Masayuki Tobita, Isamu Tominaga, Hidehiko Kikuchi

    IEEE TRANSACTIONS ON MAGNETICS   45 ( 3 ) 972 - 975  2009年03月

     概要を見る

    This paper reports a large-scale eddy-current analysis of conductive frame of large-capacity inverter. The eddy-current loss obtained by the electromagnetic field analysis is used as a heat source for the thermal analysis. Then, the suitable configuration of the frame for the suppression of temperature increase is investigated and designed. The hybrid finite-element and boundary-element (FE-BE) method is very suitable for the analysis of a complicated-shaped frame because it does not require mesh division for a free space and can easily treat eddy current. For the reduction of large computational costs, the fast multipole method (FMM) is introduced. Furthermore, in order to improve the convergence characteristic of iterative methods for system matrix, we develop the application of the IDR(s) method to the minor iterative preconditioning technique (MIP) and evaluate the performance. Finally, some numerical results that demonstrate the effectiveness of the developed method are presented.

    DOI

  • Starting Procedure of Rotational Sensorless PMSM in the Rotating Condition

    Shun Taniguchi, Shinsuke Mochiduki, Toshifumi Yamakawa, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS   45 ( 1 ) 194 - 202  2009年01月

     概要を見る

    This paper investigates a starting procedure of rotational sensorless permanent magnet synchronous motor (PMSM) in the rotating condition, which is suitable for some applications with higher maximum rotor frequency and longer current sampling time. Instantaneous estimation of initial rotor position and frequency, right after gates start, is essential for restarting the operation of inverters. Existing estimation methods are not available for the aforementioned applications because of their higher maximum rotor frequency and longer current sampling time. To cope with this problem, we propose a novel initial rotor frequency estimation method. The proposed estimation method is verified by experiments using a 2-kW interior PMSM and a numerical simulation.

    DOI

  • Control method for harmonic voltage injection to achieve noise reduction in position-sensorless control of permanent-magnet synchronous motors at low speeds

    Shun Taniguchi, Toshihiro Homma, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    IEEJ Transactions on Industry Applications   129 ( 4 ) 5 - 388  2009年

     概要を見る

    In this study, we examine the relationship between harmonic voltage injection, acoustic noise, and position estimation performance in a PMSM when a position-sensorless control method involving harmonic voltage injection is used at low speeds. Further, we propose a novel control method for voltage injection
    this method can be used to reduce acoustic noise in the motor. The proposed control method is verified by performing numerical simulations and carrying out experiments using a 4-pole, 2-kW, 2100-rpm IPMSM (interior permanent-magnet synchronous motor). © 2009 The Institute of Electrical Engineers of Japan.

    DOI

  • Starting Procedure of Rotational Sensorless PMSM in the Rotating Condition

    Shun Taniguchi, Shinsuke Mochiduki, Toshifumi Yamakawa, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS   45 ( 1 ) 194 - 202  2009年01月

     概要を見る

    This paper investigates a starting procedure of rotational sensorless permanent magnet synchronous motor (PMSM) in the rotating condition, which is suitable for some applications with higher maximum rotor frequency and longer current sampling time. Instantaneous estimation of initial rotor position and frequency, right after gates start, is essential for restarting the operation of inverters. Existing estimation methods are not available for the aforementioned applications because of their higher maximum rotor frequency and longer current sampling time. To cope with this problem, we propose a novel initial rotor frequency estimation method. The proposed estimation method is verified by experiments using a 2-kW interior PMSM and a numerical simulation.

    DOI

  • PMSM低速域位置センサレス制御における高調波電圧重畳可変制御による騒音低減法

    谷口 峻, 本間俊宏, 若尾真治, 近藤圭一郎, 米山 崇

    電気学会論文誌D   129 ( 4 ) 5 - 388  2009年

    DOI

  • Robust design optimization approach by combination of sensitivity analysis and sigma level estimation

    Naoki Nishida, Yasuhito Takahashi, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   44 ( 6 ) 998 - 1001  2008年06月

     概要を見る

    This paper proposes a novel robust optimization approach by combination of sensitivity analysis and sigma level estimation in multi-objective problems. In order to obtain robust Pareto-optima within acceptable computational costs, we actively reuse the already calculated data for the sensitivity analysis in multipoint search algorithm. The sigma level estimation is also utilized to select the significant solutions from a large number of Pareto-optima based on both the robustness and the performance. Some numerical results that verify the effectiveness of the proposed methods are presented.

    DOI

  • Loss analysis of permanent-magnet synchronous motor using three-dimensional finite-element method with homogenization method

    Y. Takahashi, S. Wakao, M. Kondo, N. Terauchi

    JOURNAL OF APPLIED PHYSICS   103 ( 7 )  2008年04月

     概要を見る

    This paper describes an iron-loss analysis of permanent-magnet synchronous motor (PMSM) taking into account lamination of iron core by a finite-element method (FEM) with a homogenization method. The detailed modeling of the laminated structure by the FEM with gap elements and double nodes requires a huge number of elements, which results in the limitation of the problem size. In order to reduce the computational costs, we apply the homogenization method to iron-loss analyses of a skewed interior PMSM and a surface permanent-magnet motor with overhanging magnet. For the clarification of the effectiveness, the homogenization method is compared with the detailed modeling from the viewpoints of computational costs and accuracy. As a consequence, it is verified that the homogenization method can analyze magnetic fields in a laminated iron core of a practical electric machine within acceptable computational costs.

    DOI

  • Loss analysis of permanent-magnet synchronous motor using three-dimensional finite-element method with homogenization method

    Y. Takahashi, S. Wakao, M. Kondo, N. Terauchi

    JOURNAL OF APPLIED PHYSICS   103 ( 7 ) 07F126  2008年04月

     概要を見る

    This paper describes an iron-loss analysis of permanent-magnet synchronous motor (PMSM) taking into account lamination of iron core by a finite-element method (FEM) with a homogenization method. The detailed modeling of the laminated structure by the FEM with gap elements and double nodes requires a huge number of elements, which results in the limitation of the problem size. In order to reduce the computational costs, we apply the homogenization method to iron-loss analyses of a skewed interior PMSM and a surface permanent-magnet motor with overhanging magnet. For the clarification of the effectiveness, the homogenization method is compared with the detailed modeling from the viewpoints of computational costs and accuracy. As a consequence, it is verified that the homogenization method can analyze magnetic fields in a laminated iron core of a practical electric machine within acceptable computational costs.

    DOI

  • Large-scale magnetic field analysis by the hybrid finite element-boundary element method combined with the fast multipole method

    Yasuhito Takahashi, Shinji Wakao

    ELECTRICAL ENGINEERING IN JAPAN   162 ( 1 ) 73 - 80  2008年01月

     概要を見る

    This paper describes a large-scale magnetic field analysis by means of the hybrid finite element-boundary element (FE-BE) method. The hybrid FE-BE method is well-suited for solving open electromagnetic field problems that comprise movement, nonlinear media, and eddy current. In general, however, large memory and computational costs are required due to the dense blocks in the system matrix generated by the BE part of the hybrid formulation. In order to overcome the above difficulties, we introduce the fast multipole method (FMM) to the hybrid FE-BE formulation developed by ourselves. Furthermore, we propose a novel preconditioning technique suitable for the hybrid FE-BE method with the FMM. Some numerical results that demonstrate the effectiveness of the proposed approach are also presented. (c) 2007 Wiley Periodicals, Inc.

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  • A Stability Analysis of the Mechanical Simulator for Induction Motor Speed Sensor-less Control in Ultra Lower Speed Range

    Toshihiro Homma, Shinji Wakao, Hiroyuki Shibuya, Keiichiro Kondo, Yukihiko Sato, Takemasa Furuya

    2008 IEEE 11TH WORKSHOP ON CONTROL AND MODELING FOR POWER ELECTRONICS     54 - +  2008年

     概要を見る

    For the speed sensor-less control in the ultra lower speed range, the mechanical simulator method is applied to cope with the problems due to the extremely lower induced voltage. In the method, however, the mechanical parameters' error, such as the error of the inertia, affects the starting performance. To reveal the conditions for the stable starting, we carry out the phase plane analysis under the condition that the actual inertia J changes from the set inertia J(s). Consequently, we find out J(s) &gt;= J is the condition for the stable acceleration. The derived condition is useful as a design index of the mechanical simulator. Additionally, to cope! with the large variation of the inertia, we carry out the phase plane analysis of the IM simulator method which compensates the estimation error of the rotor frequency. The analysis reveals that the method enables the stable acceleration while the estimation error of speed is remained in the case of inertia variation. Furthermore, we propose the modified IM simulator method which eliminates the deviation. By the phase plane analysis and experimental tests, we confirm the effectiveness of modified method.

    DOI

  • Advancement of analysis method for electromagnetic screening effect of viaducts for railway

    Tamio Okutani, Nobuyuki Nakamura, Natsuki Terada, Yutaka Tate, Satoshi Inada, Tomoyuki Ogawa, Yoshio Son, Shinji Wakao

    IEEJ Transactions on Industry Applications   128 ( 3 ) 20 - 320  2008年

     概要を見る

    New method to estimate electromagnetic screening effect of rigid frame viaducts has been developed. Mutual relationship among the effects of electrical connecting manner of girding bridges
    conductivity of the ground
    and harmonic frequency was identified theoretically and numerically based on the results of multiple conductor circuit model simulations and field measurements using over 3km length test cables set on a viaduct section of Shinkansen line under construction. Adding, developed modeling method to simplify the equivalent circuit of vast amount of steel bars in the reinforced concrete accelerates the estimation process with enough accuracy. As the result, it became easy to calculate the induced voltage in the cables or in the track circuits with enough accuracy. © 2008 The Institute of Electrical Engineers of Japan.

    DOI

  • 鉄道高架橋の電磁遮蔽効果解析手法の高度化

    奥谷民雄, 中村信幸, 寺田夏樹, 舘 裕, 稲田 聡, 小川知行, 孫 佳男, 若尾真治

    電気学会論文誌D   128 ( 3 ) 20 - 320  2008年

    DOI

  • Design estimation of the hybrid power source railway vehicle based on the multiobjective optimization by the dynamic programming

    Tomoyuki Ogawa, Hiroaki Yoshihara, Shinji Wakao, Keiichiro Kondo, Minoru Kondo

    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING   3 ( 1 ) 48 - 55  2008年01月

     概要を見る

    The power source of hybrid railway vehicles consists of both generation and energy storage devices. The hybrid vehicles have a high degree of freedom in the system design because they have different power sources. Therefore, it is difficult to establish generalized design methods of the power system. Various patterns of device capacities of generation and energy storage equipments are available for the hybrid vehicle. And various types of power control strategies are also selectable. With this background, this paper proposes a globally searched design estimation method for hybrid vehicles, which is based on multiobjective optimization by dynamic programming. The proposed method enables us to globally clarify the optimal candidates in accordance with various railway lines from a wide search domain. This results in various design concepts of the hybrid vehicles. Then, this paper confirms that the proposed method provides effective design guidelines for the conceptual design of the hybrid vehicles. Therefore the proposed method is useful for the design problem of hybrid vehicles that have a higher degree of freedom compared to electric railway vehicles. (C) 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

    DOI

  • Application of non-linear modeling methods to wind power estimation

    Yohei Watanabe, Shinji Wakao, Tsutomu Takinami, Kohei Oishi

    European Wind Energy Conference and Exhibition 2007, EWEC 2007   2   898 - 903  2007年12月

     概要を見る

    To reduce the fluctuation of wind power output by installing storage batteries to wind power generation, accurate estimation of wind power is indispensable. Calculation based on Power Curve, general method to estimate wind power output, often causes unavoidable error due to influences of time fluctuation of wind speed and direction. Therefore, we propose to apply Just-In-Time (JIT) Modeling to the estimation and the forecast of wind power output. JIT Modeling has the advantage that the algorithm is relatively simple. Compared with another non-linear modeling method, we confirmed the validation of JIT Modeling against the estimation and forecasts of wind power output through computational simulations.

  • Battery capacity estimation in wind power generation system

    Ryo Furuyama, Yohei Watanabe, Shinji Wakao

    Proceedings of the IASTED International Conference on Energy and Power Systems     321 - 325  2007年12月

     概要を見る

    For the spread of wind power generations, the technology of reducing fluctuations in wind power output is indispensable. In this research, we perform computational analyses of a wind power generation system with storage battery, and propose a novel approach for deriving the proper battery capacity. This research is to achieve sufficient smoothing of wind power output and efficient use of wind power energy. In the proposed method, numerically investigating the trade-off relationship among the smoothing effect, battery capacity, and output efficiency characteristics, we can derive the battery capacity on the basis of cost/performance. Furthermore, we performed the investigation of the system using wind power prediction method, i.e., Just-In-Time Modeling. By predicting the wind power output, we can properly update the smoothing time constant according to the short-term wind condition, which results in the reduction of battery capacity. To verify the proposed approach, we also present some computational results based on the measured data of small wind power generation system.

  • Proposal for benchmark model of laminated iron core and the large-scale and highly accurate magnetic field analysis

    Yasuhito Takahashi, Yasuhito Takahashi, Shinji Wakao, Shinji Wakao, Koji Fujiwara, Koji Fujiwara, Hiroyuki Kaimori, Hiroyuki Kaimori, Akihisa Kameari, Akihisa Kameari

    IEEJ Transactions on Power and Energy   127  2007年09月

     概要を見る

    This paper describes a benchmark model proposed for the clarification of the characteristic of various methods for modeling the laminated iron core. In order to obtain a reference solution of the benchmark model, a large-scale non-linear magnetostatic field analysis with a fine mesh enough to represent the microscopic structure of the laminated iron core is carried out by using the hybrid finite element-boundary element (FE-BE) method combined with the fast multipole method (FMM) based on diagonal forms for translation operators. The computational costs and accuracy of two kinds of the homogenization methods are discussed comparing the reference solution. As a consequence, it is verified that the homogenization methods can analyze magnetic fields in laminated iron core within acceptable computational costs.

    DOI

  • Starting procedure of rotation sensorless PMSM at coasting condition for railway vehicle traction

    Toshifumi Yamakawa, Toshifumi Yamakawa, Shinji Wakao, Shinji Wakao, Keiichiro Kondo, Keiichiro Kondo, Takashi Yoneyama, Takashi Yoneyama, Shun Taniguchi, Shun Taniguchi, Shinsuke Mochiduki, Shinsuke Mochiduki

    IEEJ Transactions on Industry Applications   127  2007年08月

     概要を見る

    This paper investigates starting procedure of rotation sensorless PMSM at coasting condition for railway vehicle traction. To realize the restarting, the initial rotor position and speed at restart are needed. The existing estimation algorithm of the initial position and speed can&#039;t be applied to railway vehicle traction because of the higher speed range and the longer current period. We propose novel estimation method of the initial speed, The estimation method is verified experimentally to ensure that it is feasible enough to be applied to the railway vehicle traction system.

    DOI

  • 積層鉄芯ベンチマークモデルの提案とその高精度磁界解析

    高橋康人, 若尾真治, 藤原耕二, 貝森弘行, 亀有昭久

    電気学会論文誌B   127-B ( 8 ) 894 - 901  2007年08月

    DOI

  • 鉄道車両駆動用PMSMにおける回転角センサレス制御時のだ行再起動

    山川隼史, 若尾真治, 近藤圭一郎, 米山 崇, 谷口 峻, 望月伸亮

    電気学会論文誌D   127-D ( 7 ) 700 - 706  2007年07月

    DOI

  • Large-scale magnetic field analysis of laminated core by using the hybrid finite element and boundary element method combined with the fast multipole method

    Yasuhito Takahashi, Shinji Wakao, Koji Fujiwara, Seiji Fujino

    IEEE TRANSACTIONS ON MAGNETICS   43 ( 6 ) 2971 - 2973  2007年06月

     概要を見る

    This paper shows a large-scale and highly accurate nonlinear magnetostatic field analysis of laminated iron core by using the hybrid finite element and boundary element (FE-BE) method. The hybrid FE-BE method is fairly effective to directly deal with the microstructure because no mesh division is required for the free space. In order to obtain the drastic reduction of the computational costs and stabilize the convergence characteristic of the Newton-Raphson method, the fast multipole method and the line search are introduced. Some numerical results that verify the effectiveness of the developed method are also presented.

    DOI

  • Advancement of analysis method for electromagnetic screening effect of mountain tunnel

    Tamio Okutani, Tamio Okutani, Nobuyuki Nakamura, Nobuyuki Nakamura, Natsuki Terada, Natsuki Terada, Mitsuyoshi Fukuda, Mitsuyoshi Fukuda, Yutaka Tate, Yutaka Tate, Satoshi Inada, Satoshi Inada, Hidenori Itoh, Hidenori Itoh, Shinji Wakao, Shinji Wakao

    IEEJ Transactions on Industry Applications   127 ( 4 ) 391 - 399  2007年04月

     概要を見る

    In this paper we report advancement of an analysis method for electromagnetic screening effect of mountain tunnel I with a multiple conductor circuit model. On A.C. electrified railways it is a great issue to manage the influence of electromagnetic induction caused by feeding circuits. Tunnels are said to have a screening effect to reduce the electromagnetic induction because a large amount of steel is used in the tunnels. But recently the screening effect is less expected because New Austrian Tunneling Method (NATM), in which the amount of steel used is less than in conventional methods, is adopted as the standard tunneling method for constructing mountain tunnels. So we measured and analyzed the actual screening effect of mountain tunnels constructed with NATM. In the process of the analysis we have advanced a method to analyze the screening effect more precisely. In this method we can adequately model tunnel structure as a part of multiple conductor circuit.

    DOI CiNii

  • 山岳トンネルの電磁遮蔽効果に対する解析手法の高度化

    奥谷民雄, 中村信幸, 寺田夏樹, 福田光芳, 舘 裕, 稲田 聡, 伊藤秀憲, 若尾真治

    電気学会論文誌D   127-D ( 4 ) 391 - 399  2007年04月

     概要を見る

    In this paper we report advancement of an analysis method for electromagnetic screening effect of mountain tunnel with a multiple conductor circuit model. On A.C. electrified railways it is a great issue to manage the influence of electromagnetic induction caused by feeding circuits. Tunnels are said to have a screening effect to reduce the electromagnetic induction because a large amount of steel is used in the tunnels. But recently the screening effect is less expected because New Austrian Tunneling Method (NATM), in which the amount of steel used is less than in conventional methods, is adopted as the standard tunneling method for constructing mountain tunnels. So we measured and analyzed the actual screening effect of mountain tunnels constructed with NATM. In the process of the analysis we have advanced a method to analyze the screening effect more precisely. In this method we can adequately model tunnel structure as a part of multiple conductor circuit.

    DOI CiNii

  • Application of stepwise multiple regression to design optimization of electric machine

    Shimpei Sonoda, Yasuhito Takahashi, Kenji Kawagishi, Naoki Nishida, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   43 ( 4 ) 1609 - 1612  2007年04月

     概要を見る

    This paper proposes the variables screening technique based on the stepwise multiple regression in multiobjective design optimization. This approach enables us to efficiently select the design variables that have a sufficient effect on machine performance. Some numerical results that demonstrate the validity of the proposed method are also presented.

    DOI

  • Large-scale and fast nonlinear magnetostatic field analysis by the magnetic moment method with the adaptive cross approximation

    Yasuhito Takahashi, Chiharu Matsumoto, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   43 ( 4 ) 1277 - 1280  2007年04月

     概要を見る

    This paper describes large-scale and fast nonlinear magnetostatic field analyses by the magnetic moment method (MMM) with the adaptive cross approximation. In order to stabilize the convergence characteristic of the Newton-Raphson method, we apply a line search technique to the MMM. Some numerical results that demonstrate the validity of the developed method are also presented.

    DOI

  • Position sensorless control of permanent magnet synchronous motor at low speed range using harmonic voltage injection

    Shun Taniguchi, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    2007 EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS, VOLS 1-10     3446 - +  2007年

     概要を見る

    This paper examines the relationship among injected harmonic voltage, acoustic noise, and position estimation error in a position sensorless control method at low speed range using harmonic voltage injection. Moreover, a novel injected voltage control method for reducing the acoustic noise is proposed. The proposed control method is verified by numerical simulations and experiments using a 4-pole, 2 kW, 2 100 rpm mini model test prototype.

    DOI

  • Energy consumption analysis of FC-EDLC hybrid railway vehicle by dynamic programming

    Tomoyuki Ogawa, Hiroaki Yoshihara, Shinji Wakao, Keiichiro Kondo, Minoru Kondo

    2007 EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS, VOLS 1-10     5190 - +  2007年

     概要を見る

    In this study, we analyze energy consumption of FC-EDLC hybrid railway vehicle to reveal the energy reduction effect. To evaluate this effect properly, we adopt dynamic programming which is optimal control theory. Dynamic programming enables us to calculate energy consumption under optimized control of power sources. In this paper, we evaluate the relationship among reduction effect of energy consumption, device capacity, and line profiles. Finally, we reveal the energy consumption characteristics and the applicability of hybrid-power-source railway vehicle.

    DOI

  • Theoretical analysis of cancellation of DC-link current harmonies in the inverter-controlled DC electric railcar

    Tomoyuki Ogawa, Shinji Wakao, Jat Taufiq, Keiichiro Kondo, Nobuo Terauchi

    2007 EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS, VOLS 1-10     5180 - +  2007年

     概要を見る

    This paper presents the theoretical studies on the DC-link current harmonics in the inverter-controlled DC electric railcar. First, we derive the mathematical expression of the harmonics. And comparison among a theoretical result, a numerical simulation result, and an experimental result is also presented for verification of the proposed theoretical analysis. Then this paper examines the harmonic cancellation effect of the phase shift operation by the derived mathematical expression.

    DOI

  • 分散型電源の導入拡大に対応した配電系統の協調運用形態

    林 泰弘, 川章司, 松木純也, 若尾真治, 馬場旬平, 北條昌秀, 横山明彦, 小林直樹, 平井崇夫, 生石光平

    電気学会論文誌B   127 ( 1 ) 41 - 52  2007年

    DOI

  • A multiobjective optimal design of a hybrid power source system for a railway vehicle

    Tomoyuki Ogawa, Tomoyuki Ogawa, Shinji Wakao, Shinji Wakao, Keiichiro Kondo, Keiichiro Kondo

    IEEJ Transactions on Industry Applications   126  2006年12月

     概要を見る

    In this paper, we study an optimal design for a hybrid power source railway vehicle as an alternative to diesel railway vehicles. The hybrid power source railway vehicle is assumed to be composed of the fuel cell and the electric double layer capacitor. We apply the multiobjective optimization based on the genetic algorithm for the vehicle design, aiming at reduction of both initial cost and energy consumption. The pareto optimal solutions are obtained using the multiobjective optimization. First we develop a simulation model of the hybrid power source railway vehicle and its electric power control methods. Next we derive the pareto optimal solutions as a result of the multiobjective optimization. Finally, we categorize the pareto optimal solutions to some groups, which enables us to elucidate characteristics of the pareto optimal solutions. Consequently, using the multiobjective optimization approach we effectively comprehend the problem characteristics and can obtain the plural valuable solutions.

    DOI

  • Fundamental study on the application of Just-In-Time Modeling to wind power estimation

    Shinji Wakao, Daisuke Hosogoshi, Tugio Yamamura

    European Wind Energy Conference and Exhibition 2006, EWEC 2006   1   412 - 416  2006年12月

     概要を見る

    In order to reduce the fluctuation of wind power output, researches on installation of storage batteries to wind power generation have been conducted. But in order to efficiently perform the charge and discharge control of storage battery, accurate estimation of wind power is required. Generally, power curve, a characteristic curve of wind power output vs. wind speed, is used for the estimation. In our research, we propose a simple and high-precision modeling method (Just-In-Time Modeling). Finally, Just-In-Time Modeling is further proved to be a more effective method through computational simulations: short-term forecasts are also discussed.

  • 鉄道車両への導入を想定したハイブリッド電源システムの多目的最適化設計

    小川知行, 若尾真治, 近藤圭一郎

    電気学会論文誌D   126-D ( 12 ) 1690 - 1698  2006年12月

    DOI

  • Large-scale and highly accurate magnetic field analysis of magnetic shield

    Y Takahashi, S Wakao, A Kameari

    JOURNAL OF APPLIED PHYSICS   99 ( 8 )  2006年04月

     概要を見る

    This paper describes a large-scale and highly accurate magnetostatic field analysis targeting a magnetic shield. The hybrid finite element-boundary element method and the magnetic moment method do not require mesh division for the free space and can easily treat the nonlinearity of magnetic property. Therefore, these methods are considered very effective for the analysis of a magnetic shield which has a high aspect ratio of the size scale to the thickness. However, large memory and computational time have been required due to the dense matrices generated by those integral-based formulations. To overcome the difficulties, we introduce the fast multipole method into the hybrid method and the magnetic moment method. Furthermore, to achieve more reduction of CPU time, we propose an effective preconditioning technique suitable for the hybrid method. Some numerical results that demonstrate the effectiveness of these approaches are also presented. (C) 2006 American Institute of Physics.

    DOI

  • Magnetic field analysis of laminated core by using homogenization method

    H Muto, Y Takahashi, S Wakao, K Fujiwara, A Kameari

    JOURNAL OF APPLIED PHYSICS   99 ( 8 )  2006年04月

     概要を見る

    This paper describes an approach to efficient modeling of the microscopic structure of magnetic materials in the nonlinear magnetostatic field analysis of a laminated core. When the ordinary finite element method is applied, large memory and computational cost are required due to the huge number of elements generated by detailed modeling of a laminated core. In order to overcome the above difficulties, we introduce the homogenization method, which is widely used in continuum mechanics, into the magnetic field computation and expand the method into the nonlinear analysis. Furthermore, the specialized homogenization method for a laminated core is carried out to verify the above homogenization method in the electromagnetism. Some numerical results are also presented to demonstrate the effectiveness of the proposed method. (C) 2006 American Institute of Physics.

    DOI

  • Magnetic field analysis of laminated core by using homogenization method

    H Muto, Y Takahashi, S Wakao, K Fujiwara, A Kameari

    JOURNAL OF APPLIED PHYSICS   99 ( 8 ) 08H907  2006年04月

     概要を見る

    This paper describes an approach to efficient modeling of the microscopic structure of magnetic materials in the nonlinear magnetostatic field analysis of a laminated core. When the ordinary finite element method is applied, large memory and computational cost are required due to the huge number of elements generated by detailed modeling of a laminated core. In order to overcome the above difficulties, we introduce the homogenization method, which is widely used in continuum mechanics, into the magnetic field computation and expand the method into the nonlinear analysis. Furthermore, the specialized homogenization method for a laminated core is carried out to verify the above homogenization method in the electromagnetism. Some numerical results are also presented to demonstrate the effectiveness of the proposed method. (C) 2006 American Institute of Physics.

    DOI

  • Large-scale and highly accurate magnetic field analysis of magnetic shield

    Y Takahashi, S Wakao, A Kameari

    JOURNAL OF APPLIED PHYSICS   99 ( 8 ) 08H904  2006年04月

     概要を見る

    This paper describes a large-scale and highly accurate magnetostatic field analysis targeting a magnetic shield. The hybrid finite element-boundary element method and the magnetic moment method do not require mesh division for the free space and can easily treat the nonlinearity of magnetic property. Therefore, these methods are considered very effective for the analysis of a magnetic shield which has a high aspect ratio of the size scale to the thickness. However, large memory and computational time have been required due to the dense matrices generated by those integral-based formulations. To overcome the difficulties, we introduce the fast multipole method into the hybrid method and the magnetic moment method. Furthermore, to achieve more reduction of CPU time, we propose an effective preconditioning technique suitable for the hybrid method. Some numerical results that demonstrate the effectiveness of these approaches are also presented. (C) 2006 American Institute of Physics.

    DOI

  • Large-scale analysis of eddy-current problems by the hybrid finite element-boundary element method combined with the fast multipole method

    Y Takahashi, S Wakao

    IEEE TRANSACTIONS ON MAGNETICS   42 ( 4 ) 671 - 674  2006年04月

     概要を見る

    This paper shows large-scale eddy-current analysis by a hybrid finite-element and boundary-element (FE-BE) method. We introduce the fast multipole method (FMM) into the two kinds of hybrid FE-BE formulations developed by ourselves. To achieve more reduction of CPU time, we propose a novel preconditioning technique suitable for the hybrid FE-BE methods with the FMM. Furthermore, we improve the FMM calculation process in the hybrid method using magnetic field intensity. Some numerical results that demonstrate the effectiveness of these approaches are also presented.

    DOI

  • Large-scale magnetic field analysis by the hybrid finite element-boundary element method combined with the fast multipole method

    Yasuhito Takahashi, Yasuhito Takahashi, Shinji Wakao, Shinji Wakao

    IEEJ Transactions on Industry Applications   126  2006年03月

     概要を見る

    This paper describes large-scale magnetic field analysis by means of the hybrid finite element-boundary element (FE-BE) method. The FE-BE method is well-suited for solving open electromagnetic field problems that comprise movement, non-linear media and eddy current. In general, however, large memory and computational costs are required due to the dense blocks in the system matrix generated by the BE part of the hybrid formulation. To overcome the above difficulties, we introduce the fast multipole method (FMM) to the FE-BE formulation developed by ourselves. Furthermore, we propose a novel preconditioning technique suitable for the hybrid FE-BE method with the FMM. Some numerical results that demonstrate the effectiveness of the proposed approach are also presented.

    DOI

  • 高速多重極法を導入した有限要素・境界要素併用法による大規模磁界解析

    高橋康人, 若尾真治

    電気学会論文誌D   126-D ( 3 ) 309 - 314  2006年03月

    DOI

  • Fundamental study on the application of Just-In-Time modeling to wind power estimation

    Daisuke Hosogoshi, Shinji Wakao, Tsugio Yamamura

    Proc. of 2006 European Wind Energy Conference (EWEC2006), Athens, Greece    2006年02月

  • A theoretical analysis of sideband harmonics on the inverter DC-link current for an electric railcar

    Tomoyuki Ogawa, Shinji Wakao, Jat Taufiq, Keiichiro Kondo, Nobuo Terauchi

    IEEJ Transactions on Industry Applications   126 ( 7 ) 1049 - 1057  2006年

     概要を見る

    The harmonics of the return current may interfere with the signaling current along with the rails. In this paper, we present the theoretical studies of the return current harmonics in the inverter-controlled DC electric railcar, aiming at contributing future work to improve the compatibility with the signaling current. We theoretically derive sideband harmonics of the DC-link current. Then, in order to verify the theoretical study, we experimentally measure the harmonics and numerically simulate the harmonics. As a result, we concluded the theoretical DC-link current is enough accurate to be utilized for the future improvement of the inverter harmonics current.

    DOI

  • Application of stepwise multiple regression to design optimization of electric machine

    Shimpei Sonoda, Yasuhito Takahasi, Kenji Kawagishi, Naoki Nishida, Shinji Wakao

    12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006    2006年

     概要を見る

    This paper proposes the variables screening technique based on the stepwise multiple regression in multi-objective design optimization. This approach enables us to efficiently select the design variables that have a sufficient effect on machine performance. Some numerical results that demonstrate the validity of the proposed method are also presented. ©2006 IEEE.

    DOI

  • Large-scale and fast nonlinear magnetostatic field analysis by the magnetic moment method with the adaptive cross approximation

    Y. Takahashi, C. Matsumoto, S. Wakao

    12th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2006    2006年

     概要を見る

    This paper describes large-scale and fast nonlinear magnetostatic field analyses by the magnetic moment method with the adaptive cross approximation (ACA). To stabilize the convergence characteristic of the Newton-Raphson method, a line search technique is also applied. Some numerical results that demonstrate the validity of the developed method are presented. © 2006 IEEE.

    DOI

  • Investigation of the storage battery station for effective utilization of electric power generated by PV clusters

    Shinji Wakao, Naoki Ueda

    CONFERENCE RECORD OF THE 2006 IEEE 4TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS 1 AND 2   2   2419 - +  2006年

     概要を見る

    The voltage of the distribution line in the district where the PV systems are clustered will be raised by reversal power flow from the PVs. Then active power control of the PV systems depresses the output. So, installing storage battery stations in the clustered PV systems is one of the means to solve the problem. Therefore, we investigated proper arrangement and control of the storage battery stations for effective utilization of the electric power generated by the PV clusters. In this paper, by means of computational simulation, we quantitatively revealed the relationship between the total amount of the storage battery capacity, the reduction rate of PV output, and the arrangement of the storage battery stations.

    DOI

  • Reduction of fuel consumption in PV/Diesel Hybrid power generation system by dynamic programming combined with genetic algorithm

    Shinji Wakao, Keigo Nakao

    CONFERENCE RECORD OF THE 2006 IEEE 4TH WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS 1 AND 2   2   2335 - +  2006年

     概要を見る

    This paper concerns a Photovoltaic / Diesel Generator hybrid power generation system with storage battery. Utilizing computational optimization methods, we carry out the optimum diesel generator operation and charge-discharge control of storage battery from the viewpoint of fuel consumption.
    Some numerical results, that demonstrate the validity of the proposed technique, are also presented. The derived trade-off relationship between the minimized fuel consumption and PV-battery capacities is useful for the design of hybrid system as quantitative indices.

    DOI

  • 高速多重極法における演算量削減に関する基礎的検討

    松本千春, 高橋康人, 若尾真治

    電気学会静止器・回転機合同研究会   SA-06-13, RM-06-13  2006年01月

  • ACAの適用による積分方程式法の大規模高速化

    高橋康人, 若尾真治

    電気学会静止器・回転機合同研究会   SA-06-12, RM-06-12  2006年01月

  • 電磁界数値解析で役立つ解析積分公式集(その7)

    松尾哲司, 藤原耕二, 濱田昌司, 亀有昭久, 若尾真治

    電気学会静止器・回転機合同研究会   SA-06-1, RM-06-1  2006年01月

  • 鉄道車両駆動用インバータにおける直流側電流の側帯高調波の理論解析

    小川知行, 若尾真治, Jat Taufiq, 近藤圭一郎, 寺内伸雄

    電気学会論文誌D   126 ( 7 ) 1049 - 1057  2006年

    DOI

  • A new flux weakening operation of interior permanent magnet synchronous motors for railway vehicle traction

    Toshifumi Yamakawa, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    2005 European Conference on Power Electronics and Applications   2005  2005年12月

     概要を見る

    This paper investigates a new flux-weakening operation of interior permanent magnet synchronous motors for railway vehicle traction. A design method of the controller is also suggested. The control method is verified both numerically and experimentally to ensure that it is feasible enough to be applied to the railway vehicle traction system.

  • 鉄道車両駆動用永久磁石同期電動機主回路システムにおける軽負荷回生制御系の設計法

    米山 崇, 近藤圭一郎, 若尾真治

    電気学会半導体電力変換/リニアドライブ合同研究会   SPC-05-131, LD-05-88  2005年12月

  • 電力エネルギー機器の高精度化を支える電磁界解析技術

    若尾真治

    電気学会「日本のライフラインを支える電力設備」シンポジウム    2005年12月

  • 電磁界解析の特質

    若尾真治

    電気学会「第15回電磁界数値解析に関するセミナー」    2005年12月

  • 磁界解析を用いた機器設計におけるデータマイニング

    若尾真治

    フォトン PHOTOシリーズ・ユーザー会in東京    2005年10月

  • Investigation of battery storage station of autonomy-enhanced PV clusters for urban community

    Masahide Yamaguchi, Tatsuya Kawamatsu, Takafumi Takuma, Kosuke Kurokawa, Kenji Otani, Shinji Wakao, Yasuhiro Hayashi, Yukiyoshi Ono

    Proc. of The 15th Intl. Photovoltaic Science and Engineering Conf. (PVSEC-15), Shanghai, China    2005年10月

  • Investigation of the configuration of autonomy-enhanced PV clusters for urban community

    Shinji Wakao, Yasuhiro Hayashi, Naoki Ueda, Akitaka Onoyama, Kosuke Kurokawa, Masahide Yamaguchi, Kenji Otani, Yukiyoshi Ono

    Proc. of The 15th Intl. Photovoltaic Science and Engineering Conf. (PVSEC-15), Shanghai, China    2005年10月

  • 幾何マルチグリッド法におけるメッシュコースニングに関する検討

    三輪將彦, 西尾隆行, 山田 隆, 若尾真治

    電気学会静止器・回転機合同研究会   SA-05-80,RM-05-87  2005年09月

  • Box Shield Model(電気学会ベンチマークモデル)の磁界解析における大規模高精度化

    高橋康人, 松本千春, 若尾真治, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-05-70, RM-05-77  2005年09月

  • 磁界の強さHと磁気ベクトルポテンシャルAを変数とした有限要素・境界要素併用法による大規模磁界解析

    高橋康人, 若尾真治

    電気学会静止器・回転機合同研究会   SA-05-69, RM-05-76  2005年09月

  • A new flux weakening operation of interior permanent magnet synchronous motors for railway vehicle traction

    Toshifumi Yamakawa, Shinji Wakao, Keiichiro Kondo, Takashi Yoneyama

    Proc. of 11th European Conference on Power Electronics and Applications (EPE2005), Dresden, Germany   Recorded in CD-ROM  2005年09月

  • データベースに基づく風力発電機の風況−出力モデリングに関する基礎的検討

    若尾真治, 細越大資, 藤原信行, 生石光平

    平成17年電気学会電力・エネルギー部門大会   No. 245  2005年08月

  • 燃料電池ハイブリッド鉄道車両導入に向けた機器容量の検討

    小川知行, 金子晴郎, 若尾真治, 近藤圭一郎

    電気学会交通・電気鉄道/リニアドライブ合同研究会   TER-05-38, LD-05-41  2005年07月

  • 鉄道車両駆動用インバータにおける直流側電流の側帯高調波の理論解析

    小川知行, 若尾真治, Jat Taufiq, 近藤圭一郎, 寺内伸雄

    電気学会半導体電力変換/産業電力電気応用合同研究会   SPC-05-55, IEA-05-10  2005年06月

  • Conceptual Study on Autonomy-Enhanced PV Clusters for Urban Community to meet the Japanese PV2030 Requirements

    Kosuke Kurokawa, Shinji Wakao, Yasuhiro Hayashi, Itaru Ishii, Kenji Otani, Masahide Yamaguchi, Takafumi Ishii, Yukiyoshi Ono

    Proc. of The 20th European Photovoltaic Solar Energy Conference, Barcelona, Spain   Recorded in CD-ROM  2005年06月

  • Voltage control in small-scale dispersed PV power generation system of networked composition

    Shinji Wakao, Tomoyuki Mikami, Fumito Tamura

    Proc. of The 20th European Photovoltaic Solar Energy Conference, Barcelona, Spain   Recorded in CD-ROM  2005年06月

  • Stand-alone PV system design based on computational simulation

    Shinji Wakao, Daisuke Nishimori

    Proc. of The 20th European Photovoltaic Solar Energy Conference, Barcelona, Spain   Recorded in CD-ROM  2005年06月

  • Large-scale-analysis of surface charge in eddy-current problems by the fast multipole method

    Y Takahashi, Y Fujishinta, S Wakao

    IEEE TRANSACTIONS ON MAGNETICS   41 ( 5 ) 1700 - 1703  2005年05月

     概要を見る

    This paper shows a large-scale analysis of surface charge in eddy-current problems, which is useful for designing an electric machine. We introduce the fast multipole method with the pseudoparticle method into the large-scale surface charge analysis and further propose an approach to dealing with the symmetry and periodicity of the analysis model by the concept of the method of images. Some numerical results, which will show the validity of the proposed method that calculation time is reduced while maintaining high precision, are presented.

    DOI

  • Comparison between three-dimensional (3D) equivalent magnetic circuit network method and 3D finite element method for magnetic-field computation

    Y Do Chun, JE Oh, Y Fujishima, S Wakao, J Lee, YH Cho

    JOURNAL OF APPLIED PHYSICS   97 ( 10 ) 10E 105  2005年05月

     概要を見る

    In this article, in order to investigate the merits of three-dimensional (3D) equivalent magnetic circuit network (EMCN) method, a 3D standard benchmark model proposed by the Institute of Electrical Engineers of Japan is analyzed. We also examine the accuracy of analysis results, the computer storage, and the computation time through the systematical comparison between 3D EMCN method and 3D finite element method based on hexahedral edge element. The incomplete Cholesky conjugate gradient method was selected for the solver. From the results, we can confirm the usefulness of 3D EMCN method. (c) 2005 American Institute of Physics.

    DOI

  • 有限要素法による非線形/渦電流場解析の基礎

    若尾真治

    第13回磁気応用技術シンポジウム    2005年04月

  • 小規模分散ネットワ−ク構成の太陽光発電システムにおけるオンライン電圧制御手法の検討

    若尾真治, 田邨文人, 三上朋之

    平成17年電気学会全国大会   No. 7-023  2005年03月

  • 確率過程による独立型PVシステムの安定性解析

    若尾真治, 西森大祐

    平成17年電気学会全国大会   No. 7-017  2005年03月

  • 電気機器の磁界解析におけるKriging法の適用

    薗田晋平, 藤島 寧, 若尾真治

    平成17年電気学会全国大会   No. 5-227  2005年03月

  • 多線条回路網解析における大地帰路相互インピーダンスの計算方式に関する一考察

    伊藤秀憲, 若尾真治, 奥谷民雄

    平成17年電気学会全国大会   No. 5-201  2005年03月

  • インバータ直流側電流の側帯高調波の理論解析

    小川知行, 若尾真治, Jat Taufiq, 近藤圭一郎, 寺内伸雄

    平成17年電気学会全国大会   No. 5-170  2005年03月

  • 鉄道車両駆動用PMSMにおける弱め界磁制御時の1パルスモードによる駆動シミュレーション

    山川隼史, 若尾真治, 近藤圭一郎, 米山 崇

    平成17年電気学会全国大会   No. 5-169  2005年03月

  • 心筋興奮伝播現象のモデル化に関する一考察

    中島賢太郎, 田中伸彦, 藤島 寧, 脇本雄平, 若尾真治, 村田 昇, 手取屋岳夫

    平成17年電気学会全国大会   No. 3-104  2005年03月

  • 高速多重極法を導入した有限要素・境界要素併用法による大規模電磁界解析

    若尾真治

    平成17年電気学会全国大会   S. 11-4  2005年03月

  • 高速多重極法を導入した有限要素・境界要素併用法による大規模磁界解析

    高橋康人, 藤島 寧, 若尾 真治

    電気学会静止器・回転機合同研究会   SA-05-17, RM-05-17  2005年01月

  • 均質化法を用いた磁界解析に関する基礎的検討

    武藤裕之, 藤島 寧, 若尾真治, 藤原耕二

    電気学会静止器・回転機合同研究会   SA-05-16, RM-05-16  2005年01月

  • 電磁界数値解析で役立つ解析積分公式集(その6)

    若尾真治, 藤原耕二, 徳増 正, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-05-15, RM-05-15  2005年01月

  • 小規模分散ネットワーク構成の太陽光発電システムにおける電圧制御手法の検討

    若尾真治, 田邨文人, 三上朋之

    太陽/風力エネルギー講演論文集2004/日本太陽エネルギー学会     495 - 498  2004年11月

  • データベースに基づく風力発電機の風況−出力モデリングに関する基礎的検討

    若尾真治, 細越大資

    太陽/風力エネルギー講演論文集2004/日本太陽エネルギー学会     345 - 348  2004年11月

  • 風力発電システムにおける併設蓄電池の容量決定に関する一考察

    若尾真治, 大山良平, 中村秀人, 藪本俊昭

    太陽/風力エネルギー講演論文集2004/日本太陽エネルギー学会     341 - 344  2004年11月

  • Optimal multiobjective 3D design of brushless permanent magnet motor using genetic algorithm

    Yon-Do Chun, Shinji Wakao, Jae-Eung Oh, Ju Lee

    Proc. of The 49th Conf. on Magnetism and Magnetic Materials (MMM’04), Jacksonville, USA     375  2004年11月

  • Hybrid Wind/PV power generation system for beacon

    Shinji Wakao, Yasuhiro Kanata

    Proc. of European Wind Energy Conference (2004 EWEC), London, UK   Recorded in CD-ROM  2004年11月

  • Novel design method of optimal battery capacity in wind power generation system

    Shinji Wakao, Ryohei Ohyama

    Proc. of European Wind Energy Conference (2004 EWEC), London, UK   Recorded in CD-ROM  2004年11月

  • Rotor Design of Permanent Magnet Synchronous Motor for Railway Vehicle

    Minoru Kondo, Keiichiro Kondo, Yasushi Fujishima, Shinji Wakao

    IEEJ Transactions on Industry Applications   124 ( 1 ) 124 - 130  2004年09月

     概要を見る

    The permanent magnet synchronous motor (PMSM) is an efficient machine, which has found application over wide power and speed ranges. This paper presents the optimal rotor design of a PMSM for use on a railway vehicle. This design utilizes reluctance torque in order to develop higher torque at starting with low open circuit voltage at high speed. © 2004, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • リラクタンストルクを有効利用した鉄道車両駆動用永久磁石同期電動機の回転子設計

    近藤 稔, 近藤圭一郎, 藤島 寧, 若尾真治

    電気学会論文誌D   124 ( 1 ) 124 - 130  2004年09月

    DOI

  • Research Trend of Electromagnetic Field Computation

    Shinji Wakao

    The Ministry of Commerce, Industry and Energy (MOCIE) of Korea, Agency for Technology and Standards (ATS)    2004年08月

  • 非線形磁気特性及びメッシュの算出トルクへの影響に関する考察

    三輪將彦, 成田一行, 山田 隆, 若尾真治

    電気学会静止器・回転機合同研究会   SA-04-64, RM-04-88  2004年07月

  • 有限要素・境界要素併用法への高速多重極法導入に関する基礎的検討

    高橋康人, 藤島 寧, 若尾真治

    電気学会静止器・回転機合同研究会   SA-04-31, RM-04-90  2004年07月

  • 電磁界数値解析で役立つ解析積分公式集(その5)

    若尾真治, 藤原耕二, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-04-44, RM-04-68  2004年07月

  • 鉄道車両駆動用インバータにおける直流側電流高調波の理論解析

    小川知行, 若尾真治, 近藤圭一郎, 寺内伸雄

    電気学会半導体電力変換/産業電力電気応用合同研究会   SPC-04-100, IEA-04-27  2004年06月

  • 鉄道車両駆動用永久磁石同期電動機における制御法の実験検証

    山川隼史, 米山 崇, 若尾真治, 近藤圭一郎

    電気学会半導体電力変換/産業電力電気応用合同研究会   SPC-04-83, IEA-04-10  2004年06月

  • Study on relations among gauge conditions based on surface charge analysis

    Takayuki Koyama, Yasushi Fujishima, Shinji Wakao, Takashi Onuki

    Proc. of The 11th Biennial IEEE Conf. on Electromagnetic Field Computation (CEFC2004), Seoul, Korea     274  2004年06月

  • Multiobjective design optimization of permanent magnet synchronous motor for railway vehicle

    Yasushi Fujishima, Minoru Kondo, Keiichiro Kondo, Shinji Wakao

    Proc. of The 11th Biennial IEEE Conf. on Electromagnetic Field Computation (CEFC2004), Seoul, Korea     29  2004年06月

  • Fundamental study on the assessment of power supply ability of photovoltaic power generating system

    Takeshi Motegi, Fumito Tamura, Shinji Wakao, Kenji Otani, Kazuhiko Kato

    Proc. of The 19th European Photovoltaic Solar Energy Conference, Paris, France   ( 3 ) 2980 - 2983  2004年06月

  • A consideration of PV system design based on computational simulation

    Shinji Wakao, Naoto Sugiyama, Akira Sawada, Keiichi Sasaki, Toshiaki Mochizuki

    Proc. of The 19th European Photovoltaic Solar Energy Conference, Paris, France   ( 2 ) 2298 - 2301  2004年06月

  • Multiobjective design optimization of brushless permanent magnet motor using 3D equivalent magnetic circuit network method

    YD Chun, S Wakao, TH Kim, KB Jang, J Lee

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY   14 ( 2 ) 1910 - 1913  2004年06月

     概要を見る

    In this paper, we discuss multiobjective design optimization of brushless permanent magnet motor (BLPMM) solved by genetic algorithm (GA) and 3D equivalent magnetic circuit network (EMCN) method. In the multiobjective optimization (MO) problem, we choose the decrease of cogging torque and the increase of torque as objectives. The airgap length, teeth width and magnetization angle of permanent magnet (PM) are also selected for the design variables respectively. From the results, our approach method enabled us to efficiently obtain diverse Pareto optimal (PO) solutions from the practical point of view. The experimental results are shown to confirm the validity of the optimization results.

    DOI

  • An optimal design of interior permanent magnet synchronous motor for the next generation commuter train

    Y Fujishima, S Wakao, M Kondo, N Terauchi

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY   14 ( 2 ) 1902 - 1905  2004年06月

     概要を見る

    In this paper, we propose a computational approach to the design of an interior permanent magnet synchronous motor to clarify its optimal design applied for traction systems of the next generation commuter train. In the approach, the finite element method, the multiobjective optimization technique, and the response surface methodology are effectively introduced. This approach enables us to save the CPU-time dramatically without degrading accuracies. Additionally, the proposed approach provides the effective information to design engineers. Finally we validate the proposed approach.

    DOI

  • 自然エネルギー発電を含む電力システムの動特性解析

    若尾真治

    第4回制御部門大会資料     745 - 750  2004年05月

  • Optimal electrical parameters for torque ripple reduction in switched reluctance motor

    Yon-Do Chun, Yasushi Fujishima, Shinji Wakao, Jea-Hak Choi, Ju Lee

    Computational Engineering I, Japan Society for Computational Methods in Engineering     199 - 208  2004年02月

  • Theoretical analysis of return current harmonics in the inverter-controlled DC electric railcar

    T Ogawa, S Wakao, K Kondo, N Terauchi

    PESC 04: 2004 IEEE 35TH ANNUAL POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-6, CONFERENCE PROCEEDINGS   1   711 - 716  2004年

     概要を見る

    The harmonics of the return current may interfere with the signaling current along with the rails. In order to investigate the index of the compatibility with the signaling current, the theoretical investigation of the return current harmonics is preferable rather than expensive and time consuming experimental study.
    In this paper, we present the theoretical studies of the return current harmonics with the asynchronous type two-step PWM in the inverter-controlled DC electric railcar, aiming at contributing future work to improve the compatibility with the signaling current.
    We analyze the return current harmonics by the following two methods. The first one is to derive theoretically the return current harmonics with the motor current harmonics approximation. The second one is to simulate numerically a traction circuit including a inverter and a motor, in order to verify theoretically derived return current. Comparing the both results, we concluded the theoretical return current is enough accurate to be utilized for the future improvement of inverter harmonics current.

    DOI

  • Field-weakening scheme combined with saturated voltage control strategy

    F Yusivar, S Wakao

    Proceedings of the 23rd IASTED International Conference on Modelling, Identification, and Control   23   417 - 422  2004年

     概要を見る

    In this paper, a novel field-weakening scheme which is combined with a saturated voltage control strategy is proposed and its performance comparison with the previous scheme (without implementing the saturation strategy) is presented. Though the proposed scheme is quite simple, it is effective to provide a higher torque capability than the previous scheme does. The maximum torque is produced by increasing the flux-producing current as much as possible while the stator voltage reference is saturated. The voltage saturation condition is stimulated by adding the torque-producing current into the flux-producing current reference. Since the DC voltage utility can be improved, that hence, improve the output power in the high speed motor operation, a larger torque is produced. Experiments were carried out to verify the proposed scheme. The experimental results of the previous scheme are also presented for comparison purposes.

  • 導体表面電荷解析への高速多重極法の適用

    高橋康人, 藤島 寧, 若尾真治

    電気学会静止器・回転機合同研究会   SA-04-2,RM-04-2  2004年01月

  • 電磁界数値解析で役立つ解析積分公式集(その4)

    若尾真治, 藤原耕二, 野口 聡, 松尾 哲司, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-04-1, RM-04-1  2004年01月

  • Design approach for linear induction motor based on surface charge analysis

    Yasushi Fujishima, Shinji Wakao, Tugio Yamamura

    Proc. of 9th Joint MMM-Intermag Conf.     111 - 112  2004年01月

  • Theoretical analysis of return current harmonics in the inverter-controlled DC electric railcar

    T Ogawa, S Wakao, K Kondo, N Terauchi

    PESC 04: 2004 IEEE 35TH ANNUAL POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-6, CONFERENCE PROCEEDINGS   Recorded in CD-ROM   711 - 716  2004年

     概要を見る

    The harmonics of the return current may interfere with the signaling current along with the rails. In order to investigate the index of the compatibility with the signaling current, the theoretical investigation of the return current harmonics is preferable rather than expensive and time consuming experimental study.
    In this paper, we present the theoretical studies of the return current harmonics with the asynchronous type two-step PWM in the inverter-controlled DC electric railcar, aiming at contributing future work to improve the compatibility with the signaling current.
    We analyze the return current harmonics by the following two methods. The first one is to derive theoretically the return current harmonics with the motor current harmonics approximation. The second one is to simulate numerically a traction circuit including a inverter and a motor, in order to verify theoretically derived return current. Comparing the both results, we concluded the theoretical return current is enough accurate to be utilized for the future improvement of inverter harmonics current.

    DOI

  • 太陽光発電システムの電力供給能力評価に関する基礎的検討

    茂木威史, 若尾真治, 大谷謙仁, 加藤和彦

    太陽/風力エネルギー講演論文集2003/日本太陽エネルギー学会     441 - 444  2003年11月

  • 数値シミュレーションを用いたPVシステム設計に関する一考察

    若尾真治, 杉山直人, 澤田 彰, 佐々木恵一, 望月敏明

    太陽/風力エネルギー講演論文集2003/日本太陽エネルギー学会     429 - 432  2003年11月

  • 航路標識に対する自然エネルギーハイブリッド発電システムの開発

    若尾真治, 安藤亮平, 金田康宏

    太陽/風力エネルギー講演論文集2003/日本太陽エネルギー学会     5 - 8  2003年11月

  • Surface charge analysis in eddy current problems

    Y Fujishima, S Wakao

    ELECTRICAL ENGINEERING IN JAPAN   145 ( 1 ) 59 - 66  2003年10月

     概要を見る

    To estimate the characteristics of electric machines that have conductors of complicated shape, it is effective to analyze the surface charge related to eddy current phenomena. However, the eddy current field is generally treated as a quasi-static field in which the displacement current is neglected and the electric field is not defined in the nonconductive region in the calculation process. Therefore, when we use only theA-phi finite element method (FEM) as a field analysis method, it is difficult to calculate the surface charge directly at the interface between conductive and nonconductive regions. In this paper, with this background, we propose a novel method of analysis of the surface charge based on both the A-phi FEM with edge elements and the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results that demonstrate the validity of the proposed method are also presented, such as the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape. (C) 2003 Wiley Periodicals, Inc.

    DOI

  • CPU-time Reduction for Electric Machine Design by the Response Surface Methodology

    Yasushi Fujishima, Shinji Wakao, Koichi Matsuoka, Minoru Kondo

    IEEJ Transactions on Industry Applications   123 ( 4 ) 371 - 378  2003年09月

     概要を見る

    This article presents a fundamental study on the application of the response surface methodology to design optimization of electric machines as an effective computational approach. As usual, in designing electric machines, it is difficult to achieve an effective optimal solution by using the FEM within an acceptable CPU-time. In this article, the response surface methodology (RSM) is introduced into the design optimization approach to evaluate the objective physical quantities in much shorter time. In the RSM process, to achieve the high quality optimal solutions, it is very important to make the response surface of high quality approximation in search domains. For that reason, Design of Experiments (DOE) is applied to obtain the appropriate selections of the FEM calculating points. Additionally, the effective iterative approach is developed, which properly narrows the search domains around the solution candidates. The proposed optimization approach results in an overall increase in the optimization speed without degrading the quality of optimal solutions. Some numerical examples that demonstrate the validity of the proposed approach are also presented. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • 表面電荷解析に基づく各種ゲージの相互関係に関する考察

    若尾真治, 藤島 寧, 小山貴之, 全 衍度

    電気学会静止器・回転機合同研究会   SA-03-53,RM-03-55  2003年09月

  • 電磁界数値解析で役立つ解析積分公式集(その3)

    若尾真治, 藤原耕二, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-03-52, RM-03-54  2003年09月

  • An improvement of the regenerative brake control for DC fed railway vehicle traction

    Takashi Yoneyama, Shinji Wakao, Keiichiro Kondo, Nobuo Terauchi

    Proc. of The 6th World Congress on Railway Research (WCRR2003)     1353 - 1357  2003年09月

  • 応答曲面近似法による機器最適化計算の高速化

    藤島 寧, 若尾真治, 松岡孝一, 近藤 稔

    電気学会論文誌D   123 ( 4 ) 371 - 378  2003年09月

    DOI

  • シミュレーションによる直流インバータ車の帰線電流高調波の検討

    小川知行, 若尾真治, 近藤圭一郎

    電気学会交通・電気鉄道/リニアドライブ合同研究会   TER-03-47, LD-03-72  2003年07月

  • Surface charge analysis in eddy current problems

    Y Fujishima, S Wakao

    IEEE TRANSACTIONS ON MAGNETICS   39 ( 3 ) 1123 - 1126  2003年05月

     概要を見る

    This paper proposes a surface-charge analysis method for evaluating the characteristics of electric machines. The proposed method is based on both the three-dimensional A - phi edge finite-element method (FEM) and the boundary integral equation-method. In the proposed method, we impose the Coulomb gauge condition on the scalar potential derived from A - phi edge FEM. Some numerical results that demonstrate,the validity of the proposed method are also presented.

    DOI

  • Overhang effect analysis of brushless DC motor by 3-D equivalent magnetic circuit network method

    YD Chun, J Lee, S Wakao

    IEEE TRANSACTIONS ON MAGNETICS   39 ( 3 ) 1610 - 1613  2003年05月

     概要を見る

    This paper investigates the permanent magnet overhang effect in brushless de motor., The characteristics are analyzed according to the variation of symmetric overhang length and asymmetric overhang ratio. A three-dimensional equivalent magnetic circuit network (EMCN) method is used for the accurate and efficient analysis. From the results, it is quantitatively verified that the increase of overhang length enhances the linkage fluxes of the stator and the asymmetric overhang ratio has a large effect, on the axial magnetic force.

    DOI

  • Magnetic force characteristics according to the variation of asymmetric overhang ratio in brushless direct current motor

    YD Chun, S Wakao, J Lee

    JOURNAL OF APPLIED PHYSICS   93 ( 10 ) 8775 - 8777  2003年05月

     概要を見る

    As usual, brushless dc motor (BLDCM) has the overhang structure of which permanent magnet (PM) length is longer than the stator's stack length. Specially, in case of asymmetric overhang, we have to pay attention to the choice of suitable overhang ratio of the lower to the upper overhang length because of the effect of the ratio on the magnetic forces. In this article, the magnetic force characteristics of BLDCM with the asymmetric overhang and the cap of the rotor are analyzed. A three-dimensional equivalent magnetic circuit network (EMCN) method is used for the efficient analysis of the magnetic field. The magnetic forces and torque are calculated by Maxwell's stress tensor. The variation of magnetic force characteristics is also analyzed according to the overhang ratio. From the results, when the overhang ratio is 0.38, the axial magnetic force characteristic could be improved remarkably. The validity of the analysis results is also clarified by comparison between calculated results and measured ones. (C) 2003 American Institute of Physics.

    DOI

  • 太陽光/風力ハイブリッド発電システムの特性解析 —静岡県神子元島灯台電源システム—

    若尾真治, 安藤亮平, 金田康宏, 南 秀実, 四宮章公, 鈴木皓夫, 矢作 勝, 廣田新一, 大橋孝之, 石井 淳

    平成15年電気学会全国大会   No. 7-138  2003年03月

  • PVシステムの動作シミュレーションにおける蓄電池特性のモデリング手法

    若尾真治, 讃井太郎, 杉山直人

    平成15年電気学会全国大会   No. 7-133  2003年03月

  • PMSM駆動システムの次数を低減した状態方程式による安定性解析

    米山 崇, 若尾真治, 近藤圭一郎

    平成15年電気学会全国大会   No. 5-220  2003年03月

  • 磁気回路における穴形状の位相最適化

    若尾真治, 山田陽一郎, 藤島 寧

    平成15年電気学会全国大会   No. 5-108  2003年03月

  • 電磁界数値解析に役立つ解析積分公式の収集活動

    若尾真治, 五十嵐 一, 藤原耕二, 亀有昭久

    平成15年電気学会全国大会   No. 5-103  2003年03月

  • Computational Analysis of Photovoltaic Power Generation System for Optical Network Unit

    Shinji Wakao, Taketoshi Kusakabe, Yoshiyuki Ohashi, Naoyuki Suzuki, Hirofumi Horii

    The transactions of the Institute of Electrical Engineers of Japan.B   123 ( 3 ) 412 - 419  2003年

     概要を見る

    We have developed a novel computational simulator for a photovoltaic (PV) power generation system as an efficient design tool. The developed simulator enables us to predict the complicated performance of the whole PV system with high accuracy at short time intervals and evaluate the system quantitatively. In this paper, using the developed simulator, we quantitatively estimate the changes of PV current, battery voltage, battery discharging current, commercial supply current, and the period of practicable stand-alone operation, etc., according to the reduction of PV/battery capacity. To confirm the validity of the developed simulator, we compare the calculated values with measured ones. The computational results precisely agree with the measured values under various PV/battery capacity conditions. Furthermore, altering PV/battery capacity in the simulation, we successfully predict the system performance, e.g., the period of practicable stand-alone operation, and evaluate the PV system parameters. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • Performance analysis of the PV/Wind/Wave hybrid power generation system

    S Wakao, R Ando, H Minami, F Shinomiya, A Suzuki

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2337 - 2340  2003年

     概要を見る

    We proposed a novel design method of PV/Wind/Wave hybrid power generation system, and have presented the validity of the system based on several simulation results([1]). By applying the proposed method, several systems were actually constructed. Furthermore, the proposed method has been also verified by the analysis based on the measured data.

  • Small-scale distributed PV power generation system of networked composition

    S Wakao, H Takano, N Nakada, T Motegi

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2298 - 2301  2003年

     概要を見る

    In this papers for further popularizing PV systems, we propose to network and control plural dispersed PV systems in small-scale area arming to operate them against unstable weather and the complicated variation of load power. We investigate some system operation modes that enable us to realize their low dependence on commercial supply or economical benefits as added values. As for the system design approach, we examine the relation between the battery capacity and the degree of dependence on the commercial supply by computational simulation. We also consider the voltage regulation as a problem to be settled in designing the system. Experimentally clarifying the relation between the voltage and the power flow regulations in the networked system, we investigate the storage battery ability to be required for relaxation of voltage regulation.

  • Computational simulation of peak cut system composed of PV power generation and storage battery

    S Wakao, H Takano, T Motegi, H Nakamuira, T Sato, T Yabumoto

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2404 - 2407  2003年

     概要を見る

    This paper deals with the peak cut system composed of PV power generation and storage battery. Recently, the demand for electric power becomes much greater especially in summer. Therefore, cutting and shifting the peak power consumption attracts ever-increasing attention. The introduction of the peak cut system results in the extensive reduction of power charge.
    In this paper, we investigate the effective design method of both PV and storage battery capacities in the system by means of computational simulation. Some numerical results are also presented to demonstrate the validity of the proposed method.

  • 複数の評価関数を考慮した機器最適化計算の高速化に関する検討

    藤島 寧, 若尾真治, 布施賢一, 近藤 稔, 寺内伸雄

    電気学会静止器・回転機合同研究会   SA-03-16, RM-03-16  2003年01月

  • 電磁界数値解析で役立つ解析積分公式集(その2)

    若尾真治, 五十嵐 一, 藤原耕二, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-03-08, RM-03-08  2003年01月

  • 数値シミュレーションによる光ファイバ終端機器用太陽光自立電源システムの特性解析

    若尾真治, 日下部壮俊, 大橋功幸, 鈴木直幸, 堀井洋史

    電気学会論文誌B   123 ( 3 ) 412 - 419  2003年

    DOI

  • Computational simulation of peak cut system composed of PV power generation and storage battery

    S Wakao, H Takano, T Motegi, H Nakamuira, T Sato, T Yabumoto

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2404 - 2407  2003年

     概要を見る

    This paper deals with the peak cut system composed of PV power generation and storage battery. Recently, the demand for electric power becomes much greater especially in summer. Therefore, cutting and shifting the peak power consumption attracts ever-increasing attention. The introduction of the peak cut system results in the extensive reduction of power charge.
    In this paper, we investigate the effective design method of both PV and storage battery capacities in the system by means of computational simulation. Some numerical results are also presented to demonstrate the validity of the proposed method.

  • Performance analysis of the PV/Wind/Wave hybrid power generation system

    S Wakao, R Ando, H Minami, F Shinomiya, A Suzuki

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2337 - 2340  2003年

     概要を見る

    We proposed a novel design method of PV/Wind/Wave hybrid power generation system, and have presented the validity of the system based on several simulation results([1]). By applying the proposed method, several systems were actually constructed. Furthermore, the proposed method has been also verified by the analysis based on the measured data.

  • Small-scale distributed PV power generation system of networked composition

    S Wakao, H Takano, N Nakada, T Motegi

    PROCEEDINGS OF 3RD WORLD CONFERENCE ON PHOTOVOLTAIC ENERGY CONVERSION, VOLS A-C   C   2298 - 2301  2003年

     概要を見る

    In this papers for further popularizing PV systems, we propose to network and control plural dispersed PV systems in small-scale area arming to operate them against unstable weather and the complicated variation of load power. We investigate some system operation modes that enable us to realize their low dependence on commercial supply or economical benefits as added values. As for the system design approach, we examine the relation between the battery capacity and the degree of dependence on the commercial supply by computational simulation. We also consider the voltage regulation as a problem to be settled in designing the system. Experimentally clarifying the relation between the voltage and the power flow regulations in the networked system, we investigate the storage battery ability to be required for relaxation of voltage regulation.

  • 太陽光/風力/波力ハイブリッド発電システムの開発と今後の展開

    若尾真治

    技術情報センター講習会テキスト“分散型ハイブリッド電源システムの開発と今後の展開”     31 - 41  2002年11月

  • 誘導電動機回生時のブロック線図による安定性解析

    佐藤光裕, フェリ・ユシバル, 若尾真治, 近藤圭一郎

    半導体電力変換・産業電力電気応用合同研究会   SPC-02-99, IEA-02-40  2002年11月

  • 蓄電池併設太陽光発電ピークカットシステムにおけるPV容量のシミュレーション評価

    若尾真治, 高野博光, 中村秀人, 佐藤敏幸, 薮本俊昭

    太陽/風力エネルギー講演論文集2002/日本太陽エネルギー学会     147 - 150  2002年11月

  • Multiobjective design optimization of interior permanent magnet synchronous motor by the response surface methodology

    Yasushi Fujishima, Shinji Wakao, Kenichi Fuse, Nobuo Terauchi, Minoru Kondo

    Proc. of The 47th Conf. on Magnetism and Magnetic Materials (MMM'02)     444  2002年11月

  • Surface Charge Analysis in Eddy Current Problems

    Yasushi Fujishima, Shinji Wakao

    IEEJ Transactions on Industry Applications   122 ( 6 ) 633 - 639  2002年09月

     概要を見る

    To estimate characteristics of electric machines that have conductors with complex form, it is effective to analyze the surface charge concerned with eddy current phenomena. However, the eddy current field is generally treated as quasi-static field in which the displacement current is neglected and the electric field is not defined in the non-conductive region in the calculating process. Therefore, when we adopt only the A-Ø FE method as a field analysis method, it is difficult to directly calculate the surface charge at the interface between conductive and non-conductive regions. In this paper, with this background, we propose a novel analysis method of the surface charge based both on the A-Ø formulation of 3D edge FE method and on the integral equation. This approach enables us to precisely calculate the surface charge. Some numerical results, which demonstrate the validity of the proposed method, are also presented, e.g., the surface charge analysis of linear induction motors for evaluating the relationships among the surface charge, eddy current, and conductor shape. © 2002, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • 応答曲面近似法の多目的最適化問題への応用

    藤島 寧, 若尾真治, 山田陽一郎, 勝田忠義

    電気学会静止器・回転機合同研究会   SA-02-37, RM-02-73  2002年09月

  • Magnetic field analysis using 3D equivalent magnetic circuit network method

    Yon-Do Chun, Ju Lee, Shinji Wakao

    電気学会静止器・回転機合同研究会   SA-02-36, RM-02-72  2002年09月

  • 電磁界数値解析で役立つ解析積分公式集(その1)

    若尾真治, 五十嵐 一, 藤原耕二, 亀有昭久

    電気学会静止器・回転機合同研究会   SA-02-28, RM-02-64  2002年09月

  • 周波数応答を用いた鉛畜電池の特性表現手法

    フェリ・ユシバル, 原津裕之, 佐藤光裕, 若尾真治, 近藤圭一郎, 松岡孝一, 川松達弥

    電気学会論文誌A   122-A ( 8 ) 715 - 721  2002年08月

  • An evaluating method of the iron loss in permanent magnet type synchronous motors for electric vehicle

    Yushi Kamiya, Yasushi Fujishima, Akihito Kataoka, Shinji Wakao

    Proc. of The 10th Biennial IEEE Conf. on Electromagnetic Field Computation (CEFC2002)     236  2002年06月

  • Novel approach to multiobjective design optimization of electric machine

    Shinji Wakao, Atsushi Yamashita, Yasushi Fujishima, Yoichiro Yamada

    Proc. of The 10th Biennial IEEE Conf. on Electromagnetic Field Computation (CEFC2002)     61  2002年06月

  • Application of response surface methodology to electric machine design optimization

    Yasushi Fujishima, Shinji Wakao, Tadayoshi Katsuta, Tsugio Yamamura

    Proc. of The 10th Biennial IEEE Conf. on Electromagnetic Field Computation (CEFC2002)     60  2002年06月

  • 渦電流場問題における導体表面電荷解析の基礎的検討

    藤島 寧, 若尾真治

    電気学会論文誌D   122-D ( 6 ) 633 - 639  2002年06月

    DOI

  • 短一次LIMの走行特性に対する二次側セクション境界の影響評価

    赤木雅陽, 片岡昭人, 若尾真治, 紙屋雄史, 蓼原 誠, 平瀬志朗

    第14回「電磁力関連のダイナミックス」シンポジウム/日本AEM学会     297 - 300  2002年05月

  • Design optimization of a permanent magnet synchronous motor by the response surface methodology

    Y Fujishima, S Wakao, A Yamashita, T Katsuta, K Matsuoka, M Kondo

    JOURNAL OF APPLIED PHYSICS   91 ( 10 ) 8305 - 8307  2002年05月

     概要を見る

    This article proposes an effective computational approach to design optimization of an outer-rotor type permanent magnet synchronous motor. As usual, because of the complicated rotor configuration and the complex magnetic saturation effects, it is difficult to design the lightweight permanent magnet synchronous motor structure that makes good use of reluctance torque within an acceptable CPU time. In this article, we adopt the finite element method as a magnetic field analysis method and the genetic algorithms as a search method. Furthermore, the response surface methodology, which enables us to evaluate the objective physical quantities in a much shorter time, is introduced into the above methods in the proposed approach. This optimization approach results in an overall increase in the optimization speed, that is, substantial CPU time reduction in comparison with the case of a conventional one. Some numerical results that demonstrate the validity of the proposed approach are also presented. (C) 2002 American Institute of Physics.

    DOI

  • Design optimization of electric machines based on the estimation of permeability distribution

    S Wakao, A Yamashita, Y Fujishima, T Yamamura

    JOURNAL OF APPLIED PHYSICS   91 ( 10 ) 8302 - 8304  2002年05月

     概要を見る

    We propose an optimization approach based on the estimation of permeability distribution, which enables us to make an effective objective function of optimization methods for the efficient design of magnetic devices. By the proposed approach, we can improve magnetic device characteristics by evaluating the deviation in the permeability distribution of the device as an objective function. In this approach, we separate the iron areas and calculate the permeability of each block to consider the permeability distribution. To verify the proposed approach, some numerical results, i.e., the shape optimization of ventilation holes in an induction motor, which demonstrate the validity of the proposed approach, are also presented. The optimization concept based on the estimation of permeability distribution is effective and can be readily applied to the practical design optimization of various magnetic devices. (C) 2002 American Institute of Physics.

    DOI

  • Boundary structure for improving performances of single-sided linear induction motors

    Y Kamiya, M Akagi, S Wakao

    JOURNAL OF APPLIED PHYSICS   91 ( 10 ) 6988 - 6990  2002年05月

     概要を見る

    In this paper, we propose a boundary structure for improving performances of single-sided linear induction motors. In this study, by adopting a three-dimensional finite element method, detailed phenomena at the boundary between secondary sections have been clarified from the viewpoint of propulsive force and secondary current distributions. Further, to suppress the aggravation of the characteristic caused by the secondary structural transition, we connect the secondary sections electrically. Finally, the propulsive force characteristic has been improved in spite of the existence of the boundary. (C) 2002 American Institute of Physics.

    DOI

  • 数値解析新技術の動向:電磁界解析へのメッシュレス法の適用

    若尾真治, 山下英生

    平成14年電気学会全国大会シンポジウム   S. 8-1  2002年03月

  • 小規模分散ネットワーク構成の太陽光発電システムにおける短時間電圧変動の検討

    若尾真治, 大橋功幸, 高野博光, 茂木威史

    平成14年電気学会全国大会   No. 7-068  2002年03月

  • 太陽光/風力ハイブリッド発電システムの特性解析 -北海道松前小島灯台電源システム-

    若尾真治, 堀井 洋史, 安藤亮平, 南 秀実, 四宮章公, 鈴木皓夫, 矢作 勝, 廣田新一, 大橋孝之, 石井 淳

    平成14年電気学会全国大会   No. 7-082  2002年03月

  • 短一次LIMにおける二次側セクション境界間導電性ワイヤー接続型構造の特性評価

    赤木雅陽, 片岡昭人, 若尾真治, 紙屋雄史, 蓼原 誠, 平瀬志朗

    平成14年電気学会全国大会   No. 5-260  2002年03月

  • Proposal and Performance Evaluation of the Short Primary LIM with the Secondary Sections Connected by the Conductive Wire

    Yushi Kamiya, Makoto Tadehara, Shiro Hirase, Shinji Wakao, Masataka Akagi, Akihito Kataoka

    IEEJ Transactions on Industry Applications   122 ( 12 ) 1129 - 1134  2002年

     概要を見る

    In this paper, we propose a boundary structure for improving performances of Single-sided Linear Induction Motors (SLIMS). In such machines, solid-plate conductors and back irons are usually used for secondary stators throughout operating regions. However, to take account of deformation due to thermal expansions, secondary stators are constructed from some sections of limited length. Therefore, a propulsive force characteristic declines when the primary armature crosses the boundary between secondary sections. In this study, by adopting a three-dimensional finite element method, detailed phenomena at the boundary between secondary sections have been clarified from the viewpoint of propulsive force and secondary current distributions. Besides the validity of calculated results is verified by the measured results. Further, to suppress the aggravation of characteristic caused by the secondary structural transition, we connect the secondary sections electrically. Finally, the propulsive force characteristic has been improved in spite of the existence of the boundary. © 2002, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • CPU-Time Reduction for Steady-State Solution in Time-Stepping FE Analysis of Rotating Machinery

    S. Wakao, N. Nishioka

    IEEJ Transactions on Industry Applications   122 ( 4 ) 390 - 395  2002年

     概要を見る

    In analyzing electrical apparatus excited from a constant voltage source such as rotating machines by the time-stepping Finite Element method, undesirable initial values often cause a large number of iterations and thus result in a long computing time. In this paper, with this background, we propose a novel acceleration method that improves the convergence characteristics of the time-stepping FE analysis for a motor excited from a constant voltage source. The proposed method enables us to sufficiently reduce the computing time by providing appropriate initial values to unknowns. In the method, the primary and secondary currents of an induction motor in steady-state operation are precisely estimated by means of both the equivalent circuit of a motor and the initial transient waveform of the currents obtained by the FE analysis, Finally, some numerical results, which demonstrate the validity of the proposed method, are also presented. © 2002, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • 最適化計算への応答曲面近似法の適用に関する基礎的検討

    藤島 寧, 若尾真治, 勝田忠義, 松岡孝一, 近藤 稔

    電気学会静止器・回転機合同研究会   SA-02-6,RM-02-6  2002年01月

  • 短一次リニア誘導モータにおける二次セクション境界間導電性ワイヤー接続型構造の提案と性能評価

    紙屋雄史, 蓼原 誠, 平瀬志朗, 若尾真治, 赤木雅陽, 片岡昭人

    電気学会論文誌D   122 ( 12 ) 1129 - 1134  2002年

    DOI

  • 回転機の動磁界解析における定常解到達時間短縮方法

    若尾真治, 西岡進夫

    電気学会論文誌D   122 ( 4 ) 390 - 395  2002年

    DOI

  • Minimum requirements of motor vector control modeling and simulation utilizing C MEX S-function in MATLAB/SIMULINK

    F. Yusivar, S. Wakao

    Proceedings of the International Conference on Power Electronics and Drive Systems   1   315 - 321  2001年12月

     概要を見る

    This paper describes a simple way to utilize C MEX S-function in MATLAB/SIMULINK for motor vector control modeling and simulation purposes. C MEX S-function is a powerful block in SIMULINK that capable to describe a dynamic system written in C language and linked into MATLAB. Basically it is categorized into three minimum structures. It is possible to model and simulate a vector-controlled motor drive with only using combination of these structures. A memory block is used for eliminating an algebraic loop so that speeding up the simulation. Simulation results will be compared with experimental ones for validation.

  • 航路標識に対する太陽光/風力/波力ハイブリッド発電システムの開発

    若尾真治

    東京電気管理技術者協会“電気管理技術”   255   2 - 12  2001年11月

  • 小規模分散ネットワーク構成の太陽光発電システムに関する基礎的検討

    若尾真治, 大橋功幸, 高野博光

    太陽/風力エネルギー講演論文集2001/日本太陽エネルギー学会     25 - 28  2001年11月

  • A novel method for evaluating the iron loss in permanent magnet type synchronous motors for electric vehicle

    Y. Kamiya, S. Wakao

    Proc. of The 46th Conf. on Magnetism and Magnetic Materials     367 - 368  2001年11月

  • 太陽光/風力/波力ハイブリッド発電システムの開発と今後の展望

    若尾真治

    技術情報センター講習会テキスト“ハイブリッド型分散電源システムの開発と今後の展望”     24 - 34  2001年10月

  • PV/Wind/Wave Hybrid Power Generation System for Beacon

    S. Wakao, T. Kusakabe, H. Horii, H. Minami, A. Suzuki, M. Yahagi, S. Hirota, Y. Ohashi, A. Ishii

    Proc. of The 17th European Photovoltaic Solar Energy Conf.     2580 - 2583  2001年10月

  • Novel modeling approach of battery characteristics in PV system simulation

    S. Wakao, T, Kusakabe,Y. Ohashi, N. Suzuki, H. Horii, T. Sanui

    Proc. of The 17th European Photovoltaic Solar Energy Conf.     2576 - 2579  2001年10月

  • Minimum requirements of motor vector control modeling and simulation utilizing C MEX S-function in MATLAB/SIMULINK

    F. Yusivar, S. Wakao

    Proc. of The fourth IEEE Intl. Conf. on Power Electronics and Drive Systems (PEDS'01)     315 - 321  2001年10月

  • The Shape Optimization of Ventilation Holes in An Induction Motor by The Hybrid Design Approach of Numerical Analysis and Analytical Design Methodology

    S. Wakao, M. Tokuhisa, A. Maeda, T. Onuki

    IEEJ Transactions on Industry Applications   121 ( 2 ) 159 - 164  2001年09月

     概要を見る

    In recent years the numerical design optimization of magnetic devices has been the focus of interest of many engineers. In designing the practical devices such as induction motors, we have to estimate many kinds of objective physical quantities in the optimization process: e.g. magnetic flux, eddy current, torque, etc. This makes it difficult to obtain the effective solution that achieves the high device performance boosts within an acceptable CPU time. Thus, some contrivances to the practical design optimization are indispensable according to the device characteristics. In this paper, with this background, we propose an effective approach to the design optimization of rotating machinery by using the numerical analysis combined with the analytical design methodology and physical considerations. To verify the proposed approach, some numerical results, i.e., the shape optimization of ventilation holes in an induction motor, are also presented. In the numerical example, our goal is to widen the ventilation hole area without making the influence of the rotor-yoke saturation more serious. © 2001, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • 数値最適化計算と電機設計法の併用による回転機通風孔の形状決定

    若尾真治, 徳久雅人, 前田篤志, 小貫 天

    電気学会論文誌D   121 ( 2 ) 159 - 164  2001年09月

    DOI

  • Acceleration of convergence characteristics of time-stepping FE analysis for rotating machines

    S Wakao, M Tokuhisa, A Maeda, N Nishioka

    IEEE TRANSACTIONS ON MAGNETICS   37 ( 5 ) 3558 - 3561  2001年09月

     概要を見る

    This paper describes a novel acceleration method that improves the convergence characteristics of the time-stepping finite element analysis for a rotating machine excited from a constant voltage source. In the proposed method, we utilize the equivalent circuit of a rotating machine and its transient current waveform characteristics. Some numerical results, which demonstrate the validity of the proposed method, are also presented.

    DOI

  • 電気学会ベンチマークモデルに対する多目的最適化計算の検討

    若尾真治, 山下 敦, J. Lee, 山田陽一郎

    電気学会静止器・回転機合同研究会   SA-01-18,RM-01-86  2001年08月

  • 導体表面電荷解析による機器特性把握の検討

    藤島 寧, 若尾真治, 勝田忠義

    電気学会静止器・回転機合同研究会   SA-01-5,RM-01-73  2001年08月

  • 電機設計への遺伝的アルゴリズムの適用に関する一考察

    若尾真治, 山下 敦, J. Lee, 山田陽一郎

    第6回日本計算工学会計算工学講演会   6 ( 1 ) 301 - 304  2001年05月

  • 渦電流場における導体表面電荷解析

    藤島 寧, 若尾真治, 勝田忠義

    第6回日本計算工学会計算工学講演会   6 ( 1 ) 297 - 300  2001年05月

  • 太陽光/風力/波力ハイブリッド発電システムにおける発電機容量配分の検討

    若尾真治, 日下部壮俊, 堀井洋史, 南 秀美, 鈴木皓夫, 矢作 勝, 廣田新一, 大橋孝之, 石井 淳

    平成13年電気学会全国大会   No. 7-201  2001年03月

  • PVシステムの数値シミュレーションにおける蓄電池特性のモデル化の検討

    若尾真治, 日下部壮俊, 大橋功幸, 鈴木直幸, 堀井洋史, 讃井太郎

    平成13年電気学会全国大会   No. 7-160  2001年03月

  • PMSM駆動用主回路の軽負荷回生時の安定性に関する一考察

    フェリ・ユシバル, 内田健司, 木原隆宏, 若尾真治, 近藤圭一郎, 松岡孝一

    平成13年電気学会全国大会   No. 5-259  2001年03月

  • 一様磁界発生装置モデルの最適化計算

    若尾真治, 山下 敦, 李 周?

    平成13年電気学会全国大会   No. 5-168  2001年03月

  • 渦電流場問題における導体表面電荷の算出

    若尾真治, 藤島 寧, 安藤弘毅

    平成13年電気学会全国大会   No. 5-150  2001年03月

  • Stability Analysis of Permanent Magnet Synchronous Motor Traction Main Circuit with Regenerative Braking on Insufficient Load's Power Consuming

    Fen Yusivar, Kenji Uchida, Takahiro Kihara, Shinji Wakao, Keiichiro Kondo, Koichi Matsuoka

    IEEJ Transactions on Industry Applications   121 ( 6 ) 651 - 657  2001年

     概要を見る

    The regenerative braking method has been employed in DC-fed electric railway vehicle traction system in order to reduce energy consumption. The load's power consuming is sometimes insufficient for the regenerated power, and it causes the input voltage of traction inverter rises. In such a case, the regenerative current is regulated to prevent the over voltage. However, in applying this regulation, especially to the permanent magnet synchronous motors (PMSM) traction system, a continuous oscillation of regenerative current is sometimes observed. Unfortunately, It deteriorates passengers' riding comfortability due to torque fluctuation. On this paper, we analyze the phenomena of the oscillation of regenerative currents and suggest an anti-oscillation regenerative current regulation method based on the analyzing results. The detail is as follows. (1) We construct a nonlinear time-varying model, which consists of the substation, power feeding system and the main traction circuit onboard and divide the nonlinear time-varying model into four linear time-invariant systems. (2) Through the analysis with the models, we make it clear that the continuouso scillationis caused by the traditional regenerative braking control method (3) Based on the analysis we suggest a novel anti-oscillation regenerative braking control method, whose effectiveness is proved through experiments. © 2001, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • vertical bar Iq vertical bar added flux weakening strategy for the rotor flux oriented control of a sinusoidal PWM VSI-fed induction motor

    F Yusivar, T Kihara, M Sato, S Wakao, T Yamamura

    IECON&apos;01: 27TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-3   2   1160 - 1165  2001年

     概要を見る

    In a conventional field oriented control of induction motor the rotor flux is assumed to be constant so that the torque is controlled by controlling the q-axis current only. In field-weakening region the rotor flux is decreased to achieve a very high rotor speed, as a consequence the available torque is reduced. In the other hand, to produce a maximum torque the rotor nux should be generated as much as possible. In this paper, a novel, simple field-weakening strategy, which provides a maximum torque capability for a sinusoidal PWM VSI-fed induction motor drive, is presented. The purpose of proposed strategy is to add the absolute q-axis current to d-axis current reference so that proper flux and torque for any given torque-producing current reference are produced automatically. The maximum torque when it is required can be obtained over the entire field-weakening region without using machine parameters or special control strategy. A saturated sinusoidal PWM is used which limits the amplitude of the inverter voltage references. As an advantage, the effective output voltage as seen by the motor is boosted. Simulation and experiment results verify the performance of the proposed method.

  • An anti oscillation strategy for the regenerative braking control of permanent magnet synchronous motor with insufficient load power consumption

    F Yusivar, K Uchida, T Kihara, S Wakao, K Kondo, K Matsuoka

    IECON&apos;01: 27TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-3   2   1457 - 1462  2001年

     概要を見る

    In a DC-fed motor drive system that implements a regenerative braking control strategy, the oscillation phenomenon in electrical system occurs due to the regenerative power regulating to prevent a DC-link over-voltage condition. In this paper the oscillation phenomenon of electrical system in the PMSM drive of railway vehicle system with a light-load regenerative braking control is pointed out. First, a simulation is carried out to confirm the oscillation phenomenon occurrence. The investigated model is then derived and its stability analysis is elucidated. Base on the analysis results a novel anti-oscillation strategy is proposed. A downsized experimental system is used for validation purpose. It Is verified that the proposed strategy eliminates the oscillation effectively.

  • An anti oscillation strategy for the regenerative braking control of permanent magnet synchronous motor with insufficient load power consumption

    F Yusivar, K Uchida, T Kihara, S Wakao, K Kondo, K Matsuoka

    IECON&apos;01: 27TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-3     1457 - 1462  2001年

     概要を見る

    In a DC-fed motor drive system that implements a regenerative braking control strategy, the oscillation phenomenon in electrical system occurs due to the regenerative power regulating to prevent a DC-link over-voltage condition. In this paper the oscillation phenomenon of electrical system in the PMSM drive of railway vehicle system with a light-load regenerative braking control is pointed out. First, a simulation is carried out to confirm the oscillation phenomenon occurrence. The investigated model is then derived and its stability analysis is elucidated. Base on the analysis results a novel anti-oscillation strategy is proposed. A downsized experimental system is used for validation purpose. It Is verified that the proposed strategy eliminates the oscillation effectively.

  • vertical bar Iq vertical bar added flux weakening strategy for the rotor flux oriented control of a sinusoidal PWM VSI-fed induction motor

    F Yusivar, T Kihara, M Sato, S Wakao, T Yamamura

    IECON&apos;01: 27TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-3     1160 - 1165  2001年

     概要を見る

    In a conventional field oriented control of induction motor the rotor flux is assumed to be constant so that the torque is controlled by controlling the q-axis current only. In field-weakening region the rotor flux is decreased to achieve a very high rotor speed, as a consequence the available torque is reduced. In the other hand, to produce a maximum torque the rotor nux should be generated as much as possible. In this paper, a novel, simple field-weakening strategy, which provides a maximum torque capability for a sinusoidal PWM VSI-fed induction motor drive, is presented. The purpose of proposed strategy is to add the absolute q-axis current to d-axis current reference so that proper flux and torque for any given torque-producing current reference are produced automatically. The maximum torque when it is required can be obtained over the entire field-weakening region without using machine parameters or special control strategy. A saturated sinusoidal PWM is used which limits the amplitude of the inverter voltage references. As an advantage, the effective output voltage as seen by the motor is boosted. Simulation and experiment results verify the performance of the proposed method.

  • 永久磁石同期電動機駆動用主回路の軽負荷回生時の安定性解析

    F. Yusivar, 内田健司, 木原隆宏, 若尾真治, 近藤圭一郎, 松岡孝一

    電気学会論文誌D   121 ( 6 ) 651 - 657  2001年

    DOI

  • 航路標識に対する太陽光/風力/波力ハイブリット発電システムの検討

    若尾真治, 日下部壮俊, 堀井洋史, 南 秀美, 鈴木皓夫, 矢作 勝, 廣田新一, 大橋孝之, 石井 淳

    太陽/風力エネルギー講演論文集2000/日本太陽エネルギー学会     139 - 142  2000年11月

  • 太陽光発電システムにおける数値シミュレーションの精度向上に関する検討

    若尾真治, 日下部壮俊, 大橋功幸, 鈴木直幸, 堀井洋史

    太陽/風力エネルギー講演論文集2000/日本太陽エネルギー学会     73 - 76  2000年11月

  • 三次元有限要素法による界磁巻線を有するLSMの特性解析

    紙屋雄史, 林 賢児, 田 宇鎮, 若尾真治

    電気学会マグネティックス・リニアドライブ研究会   MAG-00-238,LD-00-103  2000年11月

  • 短一次LIMにおける二次導体接合部渡り時の特性に関する検討

    紙屋雄史, 赤木雅陽, 若尾真治

    電気学会マグネティックス・リニアドライブ研究会   MAG-00-231,LD-00-96  2000年11月

  • 回転機における電源回路連成解析の収束性に関する一考察(その2)

    若尾真治, 前田篤志, 西岡進夫

    電気学会静止器・回転機合同研究会   SA-00-23,RM-00-88  2000年08月

  • 周波数応答を用いた蓄電池過渡特性のモデル化手法

    若尾真治, フェリ・ユシバル, 原津裕之, 近藤圭一郎, 長谷川均, 松岡孝一

    SEV/電気自動車研究会第6回研究発表全国大会     159 - 160  2000年07月

  • A novel starting and synchronizing method in the U-shaped linear hybrid motor

    S. Katoh, T. Iwamoto, W. J. Jeon, M. Akagi, Y. Kamiya, S. Wakao, T. Onuki, J. Lee

    Proc. of Intl. Conf. on Electrical Engineering (ICEE'2K)     998 - 1001  2000年07月

  • New approaches with sensorless drives

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    IEEE INDUSTRY APPLICATIONS MAGAZINE   6 ( 4 ) 44 - 50  2000年07月

    DOI

  • Design optimization of magnetic devices based on the estimation of permeability distribution

    S. Wakao, M. Tokuhisa, A. Maeda

    Proc. of The 9th IEEE Conf. on Electromagnetic Field Computation (CEFC 2000)     358  2000年06月

  • Design optimization of axially laminated rotors for synchronous reluctance motors

    S Wakao, Y Nishimura, H Ando, T Onuki

    JOURNAL OF APPLIED PHYSICS   87 ( 9 ) 6298 - 6300  2000年05月

     概要を見る

    This article describes a design optimization of an axially laminated rotor of the synchronous reluctance motor, using the optimization method combined with the magnetic field analysis. The magnetic flux distribution in the synchronous reluctance motor is distorted due to the complicated rotor configuration and the influence of magnetic saturation, which results in a large number of local minimum solutions. Therefore, taking account of the magnetic saturation by the finite element method, the authors propose a novel optimization approach by coupling the stochastic search method with the deterministic one. In the optimization process a suitable objective function for the stability of machine performances is also proposed. Finally some numerical results that demonstrate the validity of the proposed approach are presented. (C) 2000 American Institute of Physics. [S0021-8979(00)79808-2].

    DOI

  • Performance of the electromagnet type linear synchronous motor with an additional secondary solid-conductor

    W. J. Jeon, K. Hayashi, Y. Kamiya, S. Wakao, T. Onuki

    Proc. of Intl. Magnetics Conf. (INTERMAG) / IEEE    2000年04月

  • Design optimization of axially laminated rotors of synchronous reluctance motors

    S. Wakao, Y. Nishimura, H. Ando, T. Onuki

    Journal of Applied Physics / AIP   87 ( 9 ) 6298 - 6300  2000年04月

    DOI

  • PVシステムでの蓄電池充放電制御方式の比較検討

    平成12年電気学会全国大会   No. 7-203  2000年03月

  • 独立型太陽光発電システムの数値シミュレーションによる最適構成算出

    平成12年電気学会全国大会   No. 7-200  2000年03月

  • 辺要素有限要素解析におけるゲージ条件の影響

    平成12年電気学会全国大会   No. 5-168  2000年03月

  • 角棒状リニア誘導同期モータの同期化について

    平成12年電気学会全国大会   No. 5-087  2000年03月

  • 透磁率分布の評価に基づく回転子通風孔の形状最適化

    平成12年電気学会全国大会   No. 5-044  2000年03月

  • 回転機の方形波電圧駆動解析の収束性について

    平成12年電気学会全国大会   No. 5-038  2000年03月

  • 周波数応答を用いた鉛蓄電池の特性表現

    平成12年電気学会全国大会   No. 4-245  2000年03月

  • Speed adaptive observer for sensorless IM drive using combined reference frames

    Proc. of The 15th IEEE Applied Power Electronics Conf. (APEC 2000)   Vol. 1, pp. 127-132  2000年02月

  • Battery charging-discharging control method for PV system capacity reduction

    S Wakao, T Kusakabe, T Onuki, A Ishida, H Fukutomi

    CONFERENCE RECORD OF THE TWENTY-EIGHTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE - 2000     1679 - 1682  2000年

     概要を見る

    Providing against a power failure due to disasters, we have developed a photovoltaic power generation system as a back-up system for the optical network unit. Because of the restricted space in which the system is to be installed, in this paper, we intend to reduce the capacity of the developed PV system, especially the battery capacity. Considering the PV share and the commercial power supply share, we propose a novel control method of battery charging-discharging for the battery capacity reduction. According to the battery residual capacity, the control circuit manages the power flows in the system. First, we develop a precise computational simulator for the proposed system. Next, using the measured solar irradiance data, we investigate the system performances with the proposed control method by the simulator. Finally, some field trial results are also reported, which demonstrates the validity of the control method.

    DOI

  • Performance of the electromagnet type linear synchronous motor with an additional secondary solid-conductor

    Woojin Jeon, Kenji Hayashi, Yushi Kamiya, Shinji Wakao, Takashi Onuki

    Digests of the Intermag Conference    2000年01月

     概要を見る

    A novel hybrid drive that uses both linear induction motor (LIM) and linear synchronous motor (LSM) is presented. This motor consists of the primary winding energized by variable frequency supplies and the secondary having an additional solid-conductor besides the electromagnet. The effectiveness of the motor for practical use is demonstrated via experiment and finite element analysis.

  • Speed adaptive observer for Sensorless IM Drive using combined reference frames

    Feri Yusivar, Kenji Uchida, Hiroyuki Haratsu, Shinji Wakao, Takashi Onuki

    Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC   1   127 - 132  2000年01月

     概要を見る

    This paper describes a modification of the full-order observer for the Sensorless IM Drive. The modified observer uses the rotor flux calculated by the flux model instead of estimating it, thus two of the four state equations can be removed. Implementation of the modified observer provides the performance improvement of the sensorless rotor flux oriented IM drive system. The validity of the modified observer is confirmed by experiments.

  • Development of Photovoltaic System for Optical Network Unit

    Takashi Onuki, Shinji Wakao, Ryoichi Hirakawa, Taketoshi Kusakabe

    IEEJ Transactions on Industry Applications   120 ( 5 ) 718 - 724  2000年

     概要を見る

    In information lines, copper wire cables have been replaced by optical fiber cables that cannot supply power to the optical network unit (ONU). Thus, in the case of disasters, communication function paralyses may take place. Therefore, the reliability of power supply to the ONU has become important in recent years. With this background, we have developed a PV system for the ONU. In the process of development, we have proposed a novel estimation method for PV systems, that enables us to easily grasp the relationship between the instruments in the system from an overall view by regarding the instruments as the black boxes and paying attentions only to Ehe energy flows. The proposed method is useful in determining the suitable parameter arrangement of the PV system. Utilizing the method, we developed lOW order PV systems and carried out the experimental operation for one year. The experimental results showed enough system performances to meet not only the design requirement but also the spatial constraint. © 2000, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • Performance comparison of the controller configurations for the sensorless IM drive using the modified speed adaptive observer

    F Yusivar, H Haratsu, T Kihara, S Wakao, T Onuki

    EIGHTH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND VARIABLE SPEED DRIVES   ( 475 ) 194 - 200  2000年

     概要を見る

    This paper evaluates the controller configurations for the application of the modified observer introduced in our previous paper A full load disturbance is applied to each configuration to observe the load effect. A simple speed estimation adjustment procedure to minimize the speed estimation error at the desired speed is proposed. All results, are carried out through experiments.

  • Performance comparison of the controller configurations for the sensorless IM drive using the modified speed adaptive observer

    F Yusivar, H Haratsu, T Kihara, S Wakao, T Onuki

    EIGHTH INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND VARIABLE SPEED DRIVES   ( 475 ) 194 - 200  2000年

     概要を見る

    This paper evaluates the controller configurations for the application of the modified observer introduced in our previous paper A full load disturbance is applied to each configuration to observe the load effect. A simple speed estimation adjustment procedure to minimize the speed estimation error at the desired speed is proposed. All results, are carried out through experiments.

  • Battery charging-discharging control method for PV system capacity reduction

    S Wakao, T Kusakabe, T Onuki, A Ishida, H Fukutomi

    CONFERENCE RECORD OF THE TWENTY-EIGHTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE - 2000     1679 - 1682  2000年

     概要を見る

    Providing against a power failure due to disasters, we have developed a photovoltaic power generation system as a back-up system for the optical network unit. Because of the restricted space in which the system is to be installed, in this paper, we intend to reduce the capacity of the developed PV system, especially the battery capacity. Considering the PV share and the commercial power supply share, we propose a novel control method of battery charging-discharging for the battery capacity reduction. According to the battery residual capacity, the control circuit manages the power flows in the system. First, we develop a precise computational simulator for the proposed system. Next, using the measured solar irradiance data, we investigate the system performances with the proposed control method by the simulator. Finally, some field trial results are also reported, which demonstrates the validity of the control method.

    DOI

  • 光ファイバ終端機器用太陽光自立電源システムの開発

    小貫 天, 若尾真治, 平川亮一, 日下部壮俊

    電気学会論文誌D   120 ( 5 ) 718 - 724  2000年

    DOI

  • 電磁界解析技術と最適化手法の高度化

    電気学会技術報告   759号  1999年11月

  • 磁界問題における最適化設計法とその応用

    日本総合研究所JMAG User Conf. '99講演論文集/日本総合研究所    1999年11月

  • 透磁率分布の評価に基づく回転機最適化計算 −通風孔の形状決定−

    電気学会回転機研究会   RM-99-90  1999年10月

  • 大容量誘導電動機の軽量化設計

    第11回「電磁力関連のダイナミクス」シンポジウム/日本AEM学会   pp. 675-678  1999年10月

  • Practical design optimization approach for induction motors with ventilation holes

    Proc. of The 12th Conf. on the Computation of Electromagnetic Fields (COMPUMAG)   pp. 204-205  1999年10月

  • 電気機器に対する最適化設計法の適用上の問題点

    CRC総合研究所第6回MAGNAユーザー会/CRC総合研究所    1999年09月

  • Novel control method for battery charging-discharging in PV system

    Proc. of The 11th Photovoltaic Science and Engineering Conf. (PVSEC)   pp. 889-890  1999年09月

  • Investigation of PV system parameters by computational simulation

    Proc. of The 11th Photovoltaic Science and Engineering Conf. (PVSEC)   pp. 887-888  1999年09月

  • A novel structure of induction motors for weight reduction

    Proc. of the X. Intl. Symposium on Theoretical Electrical Engineering, (ISTET'99)   pp. 589-593  1999年09月

  • Sensorless control of permanent magnet synchronous motor drive using a linear reduced order observer including disturbance torque estimation

    Proc. of The 8th European Conf. on Power Electronics and Applications (EPE'99)   Recorded in CD-ROM  1999年09月

  • 回転機における電源回路連成解析の収束性に関する一考察

    電気学会静止器・回転機合同研究会   SA-99-21, RM-99-75  1999年08月

  • 周囲温度の影響を考慮した鉛蓄電池の残存容量推定

    平成11年電気学会産業応用部門大会   Vol. 1, pp. 293-294  1999年08月

  • 回転機設計に対する最適化計算の適用例

    日本能率協会第18次モータ技術フォーラム/日本能率協会    1999年06月

  • 大容量車載用モータにおける新構造の提案

    SEV/電気自動車研究会第5回研究発表全国大会   pp. 153-154  1999年06月

  • 最適化手法比較計算用モデルの解析結果(その2)

    日本計算工学会計算工学講演会   Vol. 4, No. 1, pp. 573-576  1999年05月

  • 最適化手法実用上の問題点

    平成11年電気学会全国大会シンポジウム   S. 24-4  1999年03月

  • PVシステムにおける蓄電池充放電制御方式の提案

    平成11年電気学会全国大会   No. 1865  1999年03月

  • エネルギーフロー解析に基づくPVシステム評価法

    電気学会新エネルギー・環境研究会   FTE-99-6  1999年02月

  • A new method of motor speed estimation using fuzzy logic algorithm

    F Yusivar, D Hamada, K Uchida, S Wakao, T Onuki

    IEMDC'99 - IEEE INTERNATIONAL ELECTRIC MACHINES AND DRIVES CONFERENCE, PROCEEDINGS     278 - 280  1999年

     概要を見る

    This paper describes a new simple speed estimator using fuzzy logic for improving the motor drive performance at low speed with low-resolution encoder. Since using fuzzy algorithm, the proposed technique requires no system parameter or assumption for speed estimation. Through the simulation and experiments, the proposed scheme enables to drive the motor at 25 rpm.

    DOI

  • A novel approach to design optimization of ventilation holes in induction motors

    T Onuki, S Wakao, M Tokuhisa, A Maeda

    IEMDC'99 - IEEE INTERNATIONAL ELECTRIC MACHINES AND DRIVES CONFERENCE, PROCEEDINGS     478 - 480  1999年

     概要を見る

    This paper describes a no, el approach to the design optimization of ventilation holes in induction motors. By investigating the relationship between the rotor-yoke configuration and the magnetic flux in the air-gap, we determine the desirable arrangement of ventilation holes. Some numerical results for a practical machine, which demonstrate the, validity of the proposed approach, are also presented.

    DOI

  • Stability analysis of sensorless permanent magnet synchronous motor drive with a reduced order observer

    D Hamada, K Uchida, F Yusivar, H Haratsu, S Wakao, T Onuki

    IEMDC'99 - IEEE INTERNATIONAL ELECTRIC MACHINES AND DRIVES CONFERENCE, PROCEEDINGS     95 - 97  1999年

     概要を見る

    This paper describes the stability analysis of the sensorless control system for permanent magnet synchronous motors using the reduced order observer. Deriving the equilibrium linearized state equation, we discuss the stability of the observer-based controller when the speed estimation error arises. The validity of the analysis results is confirmed by experiment.

    DOI

  • A novel approach to design optimization of ventilation holes in induction motors

    T Onuki, S Wakao, M Tokuhisa, A Maeda

    IEMDC'99 - IEEE INTERNATIONAL ELECTRIC MACHINES AND DRIVES CONFERENCE, PROCEEDINGS   pp. 478-480   478 - 480  1999年

     概要を見る

    This paper describes a no, el approach to the design optimization of ventilation holes in induction motors. By investigating the relationship between the rotor-yoke configuration and the magnetic flux in the air-gap, we determine the desirable arrangement of ventilation holes. Some numerical results for a practical machine, which demonstrate the, validity of the proposed approach, are also presented.

    DOI

  • A new method of motor speed estimation using fuzzy logic algorithm

    F Yusivar, D Hamada, K Uchida, S Wakao, T Onuki

    IEMDC'99 - IEEE INTERNATIONAL ELECTRIC MACHINES AND DRIVES CONFERENCE, PROCEEDINGS   pp. 278-280   278 - 280  1999年

     概要を見る

    This paper describes a new simple speed estimator using fuzzy logic for improving the motor drive performance at low speed with low-resolution encoder. Since using fuzzy algorithm, the proposed technique requires no system parameter or assumption for speed estimation. Through the simulation and experiments, the proposed scheme enables to drive the motor at 25 rpm.

    DOI

  • A novel optimization procedure utilizing the conformal transformation method

    T. Onuki, S. Wakao, J. W. Im, F. Ogawa, H. Takahashi

    International Journal of Applied Electromagnetics and Mechanics   9   75 - 88  1998年12月

     概要を見る

    A large number of methods for the design optimization have been proposed in recent years. However, it is not easy to apply these methods to practical use because of many iterations. So, in the design optimization, physical and engineering investigation of the given model are very important, which results in an overall increase in the optimization speed. This paper describes a novel optimization procedure utilizing the conformal transformation method. This approach consists of two phases and has the advantage of grasping the physical phenomena of the model easily. Some numerical results that demonstrate the validity of the proposed method are also presented.

  • 太陽光発電システム設計へのシミュレーションの導入

    太陽/風力エネルギー講演論文集/日本太陽エネルギー学会   No. 12,pp. 45-48  1998年12月

  • 有限要素法によるリニア誘導機解析の検証モデルの提案

    電気学会リニアドライブ研究会   LD-98-61  1998年11月

  • 電機設計法への最適化数値計算の導入 −回転機通風孔の形状決定−

    電気学会回転機研究会   RM-98-132  1998年10月

  • 最小次元オブザーバを適用したPMSMセンサレス制御の特性評価

    電気学会回転機研究会   RM-98-125  1998年10月

  • 高電力密度回転機における通風孔の形状最適化

    電気学会論文誌B   Vol. 118-B, No.10, pp. 1110-11  1998年10月

  • Design optimization of air-ducts in rotating machines with high power density

    T Onuki, S Wakao, JW Im, H Takahashi, T Miyokawa

    IEEE TRANSACTIONS ON MAGNETICS   34 ( 5 ) 2857 - 2860  1998年09月

     概要を見る

    Recently, the request for the compactness of rotating machines such as traction motors has been increasing and thus the rotating machines should be of high power density. The compactness of motors makes the problem of the magnetic saturation more serious. With this background, this paper describes the design optimization of air-ducts in induction motors. By investigating the relationship between the rotor-yoke configuration with air-ducts and the magnetic flux density in the air-gap, we determine the desirable air-ducts arrangement. Some numerical results, which demonstrate the validity of the proposed approach, are also presented.

  • 有限要素法と境界要素法の交互適用法による渦電流場解析

    電気学会静止器・回転機合同研究会   SA-98-1,RM-98-65  1998年08月

  • A novel design approach for grasping broad characteristics of magnetic shield problem

    S Wakao, T Onuki, JW Im, T Yamamura

    IEEE TRANSACTIONS ON MAGNETICS   34 ( 4 ) 2144 - 2146  1998年07月

     概要を見る

    This paper presents a novel design approach composed of two sequential processes for 3D magnetic shielding problems, which results in the global optimum solution in a shorter time. The feature of the proposed approach is the adoption of the specific boundary element with permeability of infinity. Assuming the permeability of infinity enables us to regard the thickness of ferromagnetic shields as infinitesimal, and thus to simplify the investigated model adequately in numerical analysis. This reduces the number of unknown variables and saves us a large amount of CPU-time for grasping the broad characteristics of the model. Some numerical results that demonstrate the validity of the proposed approach are also presented.

    DOI

  • The analysis of PV power system by computational simulation

    Proc. of The 2nd World Conf. and Exhibition on Photovoltaic Solar Energy Conversion   pp.3262-3265  1998年07月

  • The optimization of PV system by classifying energy flow

    Proc. of The 2nd World Conf. and Exhibition on Photovoltaic Solar Energy Conversion   pp.3258-3261  1998年07月

  • Design optimization of stimulation coil system for nerve stimulation

    T Onuki, S Wakao, T Miyokawa, Y Nishimura, N Ishikawa, H Hosaka

    IEEE TRANSACTIONS ON MAGNETICS   34 ( 4 ) 2159 - 2161  1998年07月

     概要を見る

    Magnetic stimulation therapy without pain is being studied as an alternative to electrical stimulation therapy with pain. This paper presents a novel coil arrangement including the two sub-coils besides the main coil. This scheme results in the desired Bur distribution penetrating more deeply into the tissue. Each optimal coil current and the optimal sub-coil location are derived with the aid of numerical magnetic field analysis. The derivation is carried out by means of the genetic algorithm combined with the finite element method. Moreover, we incorporate the circuit equations with the above methods. The results suggest that the magnetic stimulation with plural coils is effective for the pudendal nerve in the deep site.

  • A novel design approach for grasping broad characteristics of magnetic shield problem

    S Wakao, T Onuki, JW Im, T Yamamura

    IEEE TRANSACTIONS ON MAGNETICS   34 ( 4 ) 2144 - 2146  1998年07月

     概要を見る

    This paper presents a novel design approach composed of two sequential processes for 3D magnetic shielding problems, which results in the global optimum solution in a shorter time. The feature of the proposed approach is the adoption of the specific boundary element with permeability of infinity. Assuming the permeability of infinity enables us to regard the thickness of ferromagnetic shields as infinitesimal, and thus to simplify the investigated model adequately in numerical analysis. This reduces the number of unknown variables and saves us a large amount of CPU-time for grasping the broad characteristics of the model. Some numerical results that demonstrate the validity of the proposed approach are also presented.

  • Optimization of coils for detecting initial rotor position in permanent magnet synchronous motor

    S Wakao, T Onuki, K Tatematsu, T Iraha

    JOURNAL OF APPLIED PHYSICS   83 ( 11 ) 6365 - 6367  1998年06月

     概要を見る

    This article describes the shape optimization of detective coils for initial rotor position estimation in the drive system of permanent magnet synchronous motors. The characteristics of magnetic circuits in rotating machinery are very complicated. The magnetic flux distribution in the air gap is nonsinusoidal due to the influence of slots, magnets, and magnetic saturation, etc. By utilizing the slot ripple influence and taking the effects of both magnetic saturation and permanent magnets into consideration, an optimization of the detective coil by means of a genetic algorithm combined with a hybrid finite element and boundary element method is reported. This produces a global optimal solution in a shorter time. (C) 1998 American Institute of Physics. [S0021-8979(98)50811-0].

    DOI

  • 高電力密度回転機における通風孔の形状最適化

    日本計算工学会計算工学講演会   Vol. 3, No. 2, pp. 539-542  1998年05月

  • 大容量車載用モータにおける通風孔の形状最適化

    SEV/電気自動車研究会第4回研究発表会   pp. 121-122  1998年04月

  • 新方式の車載用モータ

    SEV/電気自動車研究会第4回研究発表会   pp. 89-90  1998年04月

  • 電磁界解析における有限要素・境界要素併用法の並列処理手法

    電気学会論文誌A   Vol. 118-A, No. 4, pp. 373-379  1998年04月

  • 数値シミュレーションによる太陽光発電システムの特性解析

    平成10年電気学会全国大会   No. 1814  1998年03月

  • エネルギー潮流の分類によるPVシステム評価法

    平成10年電気学会全国大会   No. 1813  1998年03月

  • 電気学会一様磁界発生検証モデルの最適設計

    平成10年電気学会全国大会   No. 1175  1998年03月

  • 均一磁界作成に対するコイル配置の一考察

    平成10年電気学会全国大会   No. 1174  1998年03月

  • 電気学会通風ダクト最適化モデルの形状決定

    平成10年電気学会全国大会   No. 1172  1998年03月

  • PMSMセンサレス制御への最小次元オブザーバの適用

    平成10年電気学会全国大会   No. 1004  1998年03月

  • A novel optimization procedure utilizing the conformal transformation method

    T Onuki, S Wakao, JW Im, F Ogawa, H Takahashi

    INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS   9 ( 1 ) 75 - 88  1998年03月

     概要を見る

    A large number of methods for the design optimization have been proposed in recent years. However, it is not easy to apply these methods to practical use because of many iterations. So, in the design optimization, physical and engineering investigation of the given model are very important, which results in an overall increase in the optimization speed.
    This paper describes a novel optimization procedure utilizing the conformal transformation method. This approach consists of two phases and has the advantage of grasping the physical phenomena of the model easily. Some numerical results that demonstrate the validity of the proposed method are also presented.

  • An investigation of topology optimization for 3D magnetic shielding problems

    S Wakao, T Onuki, F Ogawa

    ELECTRICAL ENGINEERING IN JAPAN   122 ( 3 ) 55 - 61  1998年02月

     概要を見る

    Novel approaches to the 3D optimal design of magnetic shields are presented, in which topology optimization is achieved with the aid of numerical magnetic field analysis. The numerical procedures are implemented by means of a genetic algorithm combined with hybrid finite element and boundary element methods. This results in an overall increase in the optimization speed with acceptable computational accuracy. Finally, we present numerical results that demonstrate the validity of the proposed approach. (C) 1998 Scripta Technica.

  • An Investigation of topology optimization for 3D magnetic shielding problems

    Shinji Wakao, Takashi Onuki, Fuyuki Ogawa

    Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)   122 ( 3 ) 55 - 61  1998年

     概要を見る

    Novel approaches to the 3D optimal design of magnetic shields are presented, in which topology optimization is achieved with the aid of numerical magnetic field analysis. The numerical procedures are implemented by means of a genetic algorithm combined with hybrid finite element and boundary element methods. This results in an overall increase in the optimization speed with acceptable computational accuracy. Finally, we present numerical results that demonstrate the validity of the proposed approach. © 1998 Scripta Technica.

    DOI

  • Optimization of coils for detecting initial rotor position in permanent magnet synchronous motor

    S. Wakao, T. Onuki, K. Tatematsu, T. Iraha

    Journal of Applied Physics   83 ( 11 ) 6365 - 6367  1998年

     概要を見る

    This article describes the shape optimization of detective coils for initial rotor position estimation in the drive system of permanent magnet synchronous motors. The characteristics of magnetic circuits in rotating machinery are very complicated. The magnetic flux distribution in the air gap is nonsinusoidal due to the influence of slots, magnets, and magnetic saturation, etc. By utilizing the slot ripple influence and taking the effects of both magnetic saturation and permanent magnets into consideration, an optimization of the detective coil by means of a genetic algorithm combined with a hybrid finite element and boundary element method is reported. This produces a global optimal solution in a shorter time. © 1998 American Institute of Physics.

    DOI

  • Sensorless permanent magnet synchronous motor drive with reduced order observer

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    APEC '98 - THIRTEENTH ANNUAL APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, VOLS 1 AND 2   1   75 - 80  1998年

     概要を見る

    In this paper we present a new approach to the sensor-less drive of permanent magnet synchronous motors based on the reduced order observer, First, we propose the new control inputs that decouple the d-axis current with the q-axis one. This enables us to construct the linear reduced order observer for estimating rotor speed and position. owing to the linearization of the motor model we can fix optimum gains of the observer under any operating condition. To confirm the validity of the proposed control scheme, experiments are carried out. The control is performed for the prototype of an eight-pole, 750W permanent magnet synchronous motor by using the software with DSP TMS320C31. The experimental results show high dynamic performance of the proposed control scheme.

  • Design optimization of air-ducts in rotating machines with high power density

    T. Onuki, S. Wakao, J. W. Im, H. Takahashi, T. Miyokawa

    IEEE Transactions on Magnetics   34 ( 5 ) 2853 - 2856  1998年

     概要を見る

    Recently, the request for the compactness of rotating machines such as traction motors has been increasing and thus the rotating machines should be of high power density. The compactness of motors makes the problem of the magnetic saturation more serious. With this background, this paper describes the design optimization of air-ducts in induction motors. By investigating the relationship between the rotor-yoke configuration with air-ducts and the magnetic flux density in the air-gap, we determine the desirable air-ducts arrangement. Some numerical results, which demonstrate the validity of the proposed approach, are also presented. © 1998 IEEE REFERENCE.

    DOI

  • Design optimization of stimulation coil system for nerve stimulation

    T. Onuki, S. Wakao, T. Miyokawa, Y. Nishimura, N. Ishikawa, H. Hosaka

    IEEE Transactions on Magnetics   34 ( 4 ) 2156 - 2158  1998年

     概要を見る

    Magnetic stimulation therapy without pain is being studied as an alternative to electrical stimulation therapy with pain. This paper presents a novel coil arrangement including the two sub-coils besides the main coil. This scheme results in the desired flux distribution penetrating more deeply into the tissue. Each optimal coil current and the optimal sub-coil location are derived with the aid of numerical magnetic field analysis. The derivation is carried out by means of the genetic algorithm combined with the finite element method. Moreover, we incorporate the circuit equations with the above methods. The results suggest that the magnetic stimulation with plural coils is effective for the pudendal nerve in the deep site. © 1998 IEEE.

    DOI

  • A novel design approach for grasping broad characteristics of magnetic shield problem

    S. Wakao, T. Onuki, J. W. Im, T. Yamamura

    IEEE Transactions on Magnetics   34 ( 4 ) 2141 - 2143  1998年

     概要を見る

    This paper presents a novel design approach composed of two sequential processes for 3D magnetic shielding problems, which results in the global optimum solution in a shorter time. The feature of the proposed approach is the adoption of the specific boundary element with permeability of infinity. Assuming the permeability of infinity enables us to regard the thickness of ferromagnetic shields as infinitesimal, and thus to simplify the investigated model adequately in numerical analysis. This reduces the number of unknown variables and saves us a large amount of CPU-time for grasping the broad characteristics of the model. Some numerical results that demonstrate the validity of the proposed approach are also presented. © 1998 IEEE.

    DOI

  • Sensorless control for permanent magnet synchronous motor with reduced order observer

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    PESC 98 RECORD - 29TH ANNUAL IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1 AND 2   1   125 - 131  1998年

     概要を見る

    This paper describes a simple sensorless control scheme for permanent magnet synchronous motors based on the reduced order observer. By introducing the new control inputs, we realize both the decoupling and the linearization of the nonlinear electrical equations. This allows us to construct the reduced order observer for estimating the rotor speed and position. Owing to the linearization of the motor model, we can fix optimum gains of the observer under any operating condition. The validity of the proposed control scheme is confirmed by experiments as embedded code in a DSP - TMS320C32. The experimental results show high dynamic performance of the proposed control scheme.

    DOI

  • Sensorless permanent magnet synchronous motor drive with reduced order observer

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    APEC '98 - THIRTEENTH ANNUAL APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, VOLS 1 AND 2   pp. 75-80   75 - 80  1998年

     概要を見る

    In this paper we present a new approach to the sensor-less drive of permanent magnet synchronous motors based on the reduced order observer, First, we propose the new control inputs that decouple the d-axis current with the q-axis one. This enables us to construct the linear reduced order observer for estimating rotor speed and position. owing to the linearization of the motor model we can fix optimum gains of the observer under any operating condition. To confirm the validity of the proposed control scheme, experiments are carried out. The control is performed for the prototype of an eight-pole, 750W permanent magnet synchronous motor by using the software with DSP TMS320C31. The experimental results show high dynamic performance of the proposed control scheme.

  • Sensorless permanent magnet synchronous motor drive with reduced order observer

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    APEC '98 - THIRTEENTH ANNUAL APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, VOLS 1 AND 2   pp. 125-131   75 - 80  1998年

     概要を見る

    In this paper we present a new approach to the sensor-less drive of permanent magnet synchronous motors based on the reduced order observer, First, we propose the new control inputs that decouple the d-axis current with the q-axis one. This enables us to construct the linear reduced order observer for estimating rotor speed and position. owing to the linearization of the motor model we can fix optimum gains of the observer under any operating condition. To confirm the validity of the proposed control scheme, experiments are carried out. The control is performed for the prototype of an eight-pole, 750W permanent magnet synchronous motor by using the software with DSP TMS320C31. The experimental results show high dynamic performance of the proposed control scheme.

    DOI

  • Sensorless permanent magnet synchronous motor drive with reduced order observer

    K Tatematsu, D Hamada, K Uchida, S Wakao, T Onuki

    APEC '98 - THIRTEENTH ANNUAL APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, VOLS 1 AND 2   pp. 95-97   75 - 80  1998年

     概要を見る

    In this paper we present a new approach to the sensor-less drive of permanent magnet synchronous motors based on the reduced order observer, First, we propose the new control inputs that decouple the d-axis current with the q-axis one. This enables us to construct the linear reduced order observer for estimating rotor speed and position. owing to the linearization of the motor model we can fix optimum gains of the observer under any operating condition. To confirm the validity of the proposed control scheme, experiments are carried out. The control is performed for the prototype of an eight-pole, 750W permanent magnet synchronous motor by using the software with DSP TMS320C31. The experimental results show high dynamic performance of the proposed control scheme.

    DOI

  • Magnetic field analysis of nonlinear system considering both motion and voltage equations

    T. Onuki, T. Nakatsu, S. Wakao, M. Hori

    IEEE Transactions on Magnetics   33   2097 - 2100  1997年12月

     概要を見る

    This paper describes the method that makes it easy to simulate the magnetic levitation system by using the Boundary Element Method (BEM) or the hybrid Finite Element(FE)-Boundary Element(BE) Method. The proposed approach enables us to simulate a nonlinear control system in consideration of both the motion equation and the voltage equation. And the voltage equation contains the term of the leakage inductance that we have to consider in the actual model. © 1997 IEEE.

    DOI

  • Hybrid Trefftz and finite element method applied to magnetic field analysis for rotating machines

    T. Onuki, S. Wakao, T. Kuwahara, Jee Won Im

    IEEE Transactions on Magnetics   33   2014 - 2017  1997年12月

     概要を見る

    This paper describes a hybrid approach of the finite element method and the boundary type solutions, i.e. the Trefftz method and the boundary element method, for analyzing the magnetic field in rotating machines. This approach has the advantage of obtaining continuous physical quantities precisely without the singularities in calculating boundary integrals. Its application to a concrete model is also presented. © 1997 IEEE.

    DOI

  • 有限要素・境界要素併用法による電気学会検証モデルの特性解析

    電気学会リニアドライブ研究会   LD-97-78  1997年08月

  • 高電力密度回転機における通風ダクトの形状最適化

    電気学会静止器・回転機合同研究会   SA-97-3, RM-97-62  1997年08月

  • 最小次元オブザーバを用いた永久磁石同期電動機のセンサレス制御

    平成9年電気学会産業応用部門全国大会   Vol. 3, No. 124, pp. 73-76  1997年08月

  • 電磁界解析における有限要素・境界要素併用法の並列処理手法

    平成9年電気学会電子・情報・システム部門大会   B-4-8  1997年08月

  • 電磁界解析における有限要素・境界要素併用法の並列処理手法

    情報処理学会研究会   97-HPC-67-3  1997年08月

  • A new design approach to the shape and topology optimization of magnetic shields

    S Wakao, T Onuki, F Ogawa

    JOURNAL OF APPLIED PHYSICS   81 ( 8 ) 4699 - 4701  1997年04月

     概要を見る

    A novel approach to the three-dimensional optimal design of magnetic shields is presented, in which both shape optimization and topology optimization are achieved with the aid of numerical magnetic-field analysis. These numerical procedures are implemented by means of the hybrid finite element and boundary element method combined with the genetic algorithm. This results in an overall increase in the optimization speed with acceptable computational accuracy. Finally, some numerical results that demonstrate the validity of the proposed approach are presented. (C) 1997 American Institute of Physics.

    DOI

  • 三次元磁気シールド問題に対する位相最適化の検討

    電気学会論文誌D   Vol. 117-D, No. 4, pp. 501-506  1997年04月

    DOI

  • 有限要素法による短二次リニア誘導モータの一次コイル結線法の検討

    早稲田大学情報科学研究教育センター紀要   Vol. 21, 96/spring, pp. 70-73  1997年03月

  • 電磁界解析のための有限要素・境界要素併用法の並列処理

    情報処理学会第54回全国大会   5F-7  1997年03月

  • 有限要素法と境界要素法の交互適用における入力電流の扱いについて

    平成9年電気学会全国大会   No. 1232  1997年03月

  • Magnetic field analysis of nonlinear system considering both motion and voltage equations

    T Onuki, T Nakatsu, S Wakao, M Hori

    IEEE TRANSACTIONS ON MAGNETICS   33 ( 2 ) 2097 - 2100  1997年03月

     概要を見る

    This paper describes the method that makes it easy to simulate the magnetic levitation system by using the Boundary Element Method (BEM) or the hybrid Finite Element(FE)-Boundary Element(BE) Method. The proposed approach enables us to simulate a nonlinear control system in consideration of both the motion equation and the voltage equation. And the voltage equation contains the term of the leakage inductance that we have to consider in the actual model.

    DOI

  • Hybrid Trefftz and finite element method applied to magnetic field analysis for rotating machines

    T Onuki, S Wakao, T Kuwahara, JW Im

    IEEE TRANSACTIONS ON MAGNETICS   33 ( 2 ) 2014 - 2017  1997年03月

     概要を見る

    This paper describes a hybrid approach of the finite element method and the boundary type solutions, i.e. the Trefftz method and the boundary element method, for analyzing the magnetic field in rotating machines. This approach has the advantage of obtaining continuous physical quantities precisely without the singularities in calculating boundary integrals. Its application to a concrete model is also presented.

    DOI

  • 有限要素・境界要素併用法の並列処理手法

    電気学会情報処理研究会   IP-96-27  1996年09月

  • 最適化問題の大域的特性把握に対する特殊境界要素の適用

    電気学会静止器・回転機合同研究会   SA-96-29, RM-96-79  1996年07月

  • 並列処理の導入による有限要素・境界要素併用解析法の高速化

    電気学会静止器・回転機合同研究会   SA-96-10, RM-96-60  1996年07月

  • Novel optimization procedure utilizing the conformal transformation method

    Proc. of The 4th Intl. Workshop on Optimization and Inverse Problems in Electromagnetism   p. 40  1996年06月

  • フィニッシュ電験三種 —機械③—

    (株)オーム社    1996年03月

  • 有限要素法によるリニアモータのうず電流場解析

    早稲田大学情報科学研究教育センター紀要   Vol. 19, 95/spring, pp. 63-70  1996年03月

  • 有限要素法と境界要素法を利用した電磁界解析の並列処理

    情報処理学会第52回全国大会   4L-8  1996年03月

  • MRIマグネットモデルに対する最適化手法の検討

    平成8年電気学会全国大会   No. 1149  1996年03月

  • 電気学会磁気シールド問題に対する位相最適化の検討

    日本シミュレーション学会第16回計算電気・電子工学シンポジウム   pp. 143-146  1995年12月

  • Hybrid FE-BE analysis of magnetic fields in rotating machinery

    Proc. of the 7th Intl. Symposium on Non-Linear Electromagnetic Systems (ISEM)   D-32  1995年09月

  • Permeance expression of magnetic circuit with consideration of eddy currents

    Proc. of the 7th Intl. Symposium on Non-Linear Electromagnetic Systems (ISEM)   D-31  1995年09月

  • 物理的・工学的考察に基づいた形状最適化手法のロバスト性

    電気学会静止器回転機合同研究会   SA-95-6, RM-95-68  1995年08月

  • 電気学会磁気シールドモデルに対する最適化の一考察

    電気学会静止器回転機合同研究会   SA-95-5, RM-95-67  1995年08月

  • Novel boundary element procedure for design optimization of magnetic shields

    Proc. of 10th Conf. on the Computation of Electromagnetic Fields (COMPUMAG)   pp. 498-499  1995年07月

  • New optimal design method on boundary element analysis for magnetic shielding

    Proc. of 14th Intl. Conf. on Magnet Technology    1995年06月

  • SYSTEMATIC EVALUATION FOR MAGNETIC-FIELD AND POTENTIAL DUE TO MASSIVE CURRENT COIL

    T ONUKI, S WAKAO

    IEEE TRANSACTIONS ON MAGNETICS   31 ( 3 ) 1476 - 1479  1995年05月

     概要を見る

    An analytical approach for calculating magnetic fields and potentials of massive current coils is presented. The proposed approach enables accurate, fast, and systematic evaluation of magnetic field intensity, vector potential, and scalar potential due to massive currents by means of simple and similar algorithms.

    DOI

  • EDDY-CURRENT COMPUTATIONS IN MOVING CONDUCTORS BY THE HYBRID FE-BE METHOD

    T ONUKI, S WAKAO, T YOSHIZAWA

    IEEE TRANSACTIONS ON MAGNETICS   31 ( 3 ) 1436 - 1439  1995年05月

     概要を見る

    This paper describes the hybrid finite element (FE) and boundary element (BE) method for the eddy current problem including moving conductors. Electromagnetic phenomena due to the three-dimensional movement of conductors can be computed easily and naturally by the presented formulation. Its application to a simple model which has only one conductor is also given.

    DOI

  • 回転機空隙磁界に対する有限要素・境界要素結合解法の適用

    日本シミュレーション学会第15回計算電気・電子工学シンポジウム   pp. 47-50  1995年03月

  • 工学的検討に基づいた電気学会最適化モデルの考察

    日本シミュレーション学会第15回計算電気・電子工学シンポジウム   pp. 19-22  1995年03月

  • 磁気シールド形状最適化問題に対する有限要素・境界要素併用法の適用

    平成7年電気学会全国大会   No. 1089  1995年03月

  • Systematic Evaluation for Magnetic Field and Potential due to Massive Current Coil

    T. Onuki, S. Wakao

    IEEE Transactions on Magnetics   31 ( 3 ) 1476 - 1479  1995年

     概要を見る

    An analytical approach for calculating magnetic fields and potentials of massive current coils is presented. The proposed approach enables accurate, fast, and systematic evaluation of magnetic field intensity, vector potential, and scalar potential due to massive currents by means of simple and similar algorithms. © 1995 IEEE.

    DOI

  • Eddy Current Computations in Moving Conductors by the Hybrid FE-BE Method

    T. Onuki, S. Wakao, T. Yoshizawa

    IEEE Transactions on Magnetics   31 ( 3 ) 1436 - 1439  1995年

     概要を見る

    This paper describes the hybrid finite element (FE) and boundary element (BE) method for the eddy current problem including moving conductors. Electromagnetic phenomena due to the three-dimensional movement of conductors can be computed easily and naturally by the presented formulation. Its application to a simple model which has only one conductor is also given. © 1995 IEEE.

    DOI

  • 導体運動を伴う渦電流場問題に対する数値解析法の検討

    電気学会回転機研究会   RM-94-126  1994年10月

  • HYBRID FINITE AND BOUNDARY-ELEMENT METHOD APPLIED TO NONLINEAR MAGNETIC-FIELD ANALYSIS

    T ONUKI, S WAKAO, T HATTORI

    IEEE TRANSACTIONS ON MAGNETICS   30 ( 5 ) 2908 - 2911  1994年09月

     概要を見る

    The finite element method (FEM) and the boundary element method (BEM) have entirely different characteristics. The FEM suits the analysis of a complicated region which includes nonlinear materials, and the BEM is useful for analyzing very large linear fields. This paper describes the hybrid finite and boundary element method which has the advantages of both methods. Here, we adopt the hybrid method to a 2D nonlinear magnetic problem with the moving boundary and make its advantages clear.

    DOI

  • IMPROVEMENT IN THE CALCULATION OF ELECTROMAGNETIC FORCE BY THE FEM

    T ONUKI, S WAKAO, H SAITO

    IEEE TRANSACTIONS ON MAGNETICS   30 ( 4 ) 1863 - 1866  1994年07月

     概要を見る

    This paper proposes a smoothing method using the boundary element method(BEM) for the finite element(FE) analysis of the electromagnetic fields. This method has the advantage of obtaining the physical quantities continuously with good precision. This approach is also easily applied to a complicated region which could include non-linear materials or eddy currents. To verify this approach, the numerical results obtained by the proposed method are compared with the theoretical values.

    DOI

  • 有限要素法・境界要素法における双対物理量数値解の特徴

    平成6年電気学会全国大会   No. 991  1994年03月

  • Improvement in the Calculation of Electromagnetic Force by the FEM

    T. Onuki, S. Wakao, H. Saito

    IEEE Transactions on Magnetics   30 ( 4 ) 1863 - 1866  1994年

     概要を見る

    This paper proposes a smoothing method using the boundary element method(BEM) for the finite element(FE) analysis of the electromagnetic fields. This method has the advantage of obtaining the physical quantities continuously with good precision. This approach is also easily applied to a complicated region which could include non-linear materials or eddy currents. To verify this approach, the numerical results obtained by the proposed method are compared with the theoretical values. © 1994 IEEE

    DOI

  • Improvement of the smoothing method in the finite element analysis

    Takashi Onuki, Shinji Wakao, Hiroshi Saito

    IEEJ Transactions on Industry Applications   114 ( 11 ) 1108 - 1114  1994年

     概要を見る

    The finite element method (FEM) and the boundary element method (BEM) are very useful for the numerical analysis of electromagnetic phenomena. Although the FEM suits the analysis of a complicated region which could include non-linear materials or eddy currents, the physical quantities such as the magnetic flux densities B are obtained discretely. Therefore we have to make fine meshes for accurate estimation of the electromagnetic force by the Maxwell stress method. On the other hand the BEM makes it possible to derive continuous physical quantities at inner points by using analytical expressions, not by relying numerical derivation as in case of the FEM. In this paper we first use the FEM for analyzing the electromagnetic fields of the concrete model in terms of the magnetic vector potential A and the electric scalar potental φ. Next we locate the temporary boundary enclosing the region where we desire the values of B, and apply the BEM (using the H method or the φ method) to this region in order to obtain B continuously. Then we can calculate the electromagnetic force accurately by the Maxwell stress method. To verify this approach, the numerical results obtained by the proposed method are compared with the theoretical values. © 1994, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • THE BOUNDARY-ELEMENT-LIKE ESTIMATION OF THE ELECTROMAGNETIC FORCE IN THE FINITE-ELEMENT METHOD

    T ONUKI, S WAKAO, H SAITO, K IKEMOTO

    SECOND INTERNATIONAL CONFERENCE ON COMPUTATION IN ELECTROMAGNETICS   ( 384 ) 247 - 250  1994年

     概要を見る

    As the analysis methods of the electromagnetic field, the finite element method (FEM) and the boundary element method (BEM) are well-known. In this paper, we propose the following method. Firstly, we analyze the investigated region only by the FEM, after that locate the hypothetical boundary properly surrounding the points where we desire the values of B in the homogeneous region. Finally, we calculate B at inner points by the BEM with the values by the FEM as the boundary conditions. Analyzing by the FEM at first, this method is easily applied to the complicated multi-material problems. We adopt several kinds of physical quantities to this method as unknowns, and also show the propriety and advantage of this method by analyzing the simple model.

  • Hybrid Finite and Boundary Element Method Applied to Nonlinear Magnetic Field Analysis

    T. Onuki, S. Wakao, T. Hattori

    IEEE Transactions on Magnetics   30 ( 5 ) 2908 - 2911  1994年

     概要を見る

    The finite element method (FEM) and the boundary element method (BEM) have entirely different characteristics. The FEM suits the analysis of a complicated region which includes nonlinear materials, and the BEM is useful for analyzing very large linear fields. This paper describes the hybrid finite and boundary element method which has the advantages of both methods. Here, we adopt the hybrid method to a 2D nonlinear magnetic problem with the moving boundary and make its advantages clear. © 1994 IEEE

    DOI

  • THE BOUNDARY-ELEMENT-LIKE ESTIMATION OF THE ELECTROMAGNETIC FORCE IN THE FINITE-ELEMENT METHOD

    T ONUKI, S WAKAO, H SAITO, K IKEMOTO

    SECOND INTERNATIONAL CONFERENCE ON COMPUTATION IN ELECTROMAGNETICS   pp. 247-250 ( 384 ) 247 - 250  1994年

  • 有限要素法解析におけるスムージング手法の改善

    電気学会論文誌D   114 ( 11 ) 1108 - 1114  1994年

    DOI

  • PHYSICAL MEANING OF GAUGE CONDITIONS IN EDDY-CURRENT ANALYSIS

    T ONUKI, S WAKAO, T YAMAMURA

    IEEE TRANSACTIONS ON MAGNETICS   29 ( 6 ) 2452 - 2454  1993年11月

     概要を見る

    There are several ways to define the gauge condition in the A - phi method for the 3-D eddy current analysis: e.g. the Coulomb gauge, the Lorentz gauge, etc. Unlike the Coulomb gauge, the physical meaning of the potentials in the Lorentz gauge is not obvious. Therefore this paper introduces a novel physical meaning of the Lorentz gauge, and describes the relationship between these gauge conditions in the A - phi method systematically from a physical viewpoint.

    DOI

  • スムージングを適用した有限要素法による電磁力計算の検討

    電気学会静止器・回転機合同研究会   SA-93-10, RM-93-48  1993年08月

  • 境界要素法における入力電流項の算定法の検討

    電気学会静止器・回転機合同研究会   SA-93-6, RM-93-45  1993年08月

  • 有限要素・境界要素併用法による三次元渦電流場の解析

    日本応用磁気学会第81回研究会   pp. 49-56  1993年07月

  • 渦電流場解析における各種物理量を用いた有限要素・境界要素併用法の比較・検討

    日本シミュレーション学会第14回計算電気・電子工学シンポジウム   pp. 25-30  1993年03月

  • ELECTROMAGNETIC-FIELD COMPUTATIONS BY THE HYBRID FE-BE METHOD USING EDGE ELEMENTS

    S WAKAO, T ONUKI

    IEEE TRANSACTIONS ON MAGNETICS   29 ( 2 ) 1487 - 1490  1993年03月

     概要を見る

    This paper presents the hybrid finite element and boundary element method using edge elements for a 3-D electromagnetic problem with open boundary. In this method we adopt the modified magnetic vector potential A* and the magnetic field intensity H as the physical quantities. The appropriate boundary element discretization described in this paper makes it easy to couple the BE region with the FE region through the transformation of unknown variables.
    To verify this approach some numerical results obtained by the proposed method are compared with measured ones.

    DOI

  • Novel boundary element analysis for 3-D eddy current problems

    IEEE Transactions on Magnetics   Vol. 29, No. 2, pp. 1520-1523  1993年03月

    DOI

  • Electromagnetic Field Computations by the Hybrid FE-BE Method using Edge Elements

    S. Wakao, T. Onuki

    IEEE Transactions on Magnetics   29 ( 2 ) 1487 - 1490  1993年

     概要を見る

    This paper presents the hybrid finite element and boundary element method using edge elements for a 3-D electromagnetic problem with open boundary. In this method we adopt the modified magnetic vector potential A* and the magnetic field intensity H as the physical quantities. The appropriate boundary element discretization described in this paper makes it easy to couple the BE region with the FE region through the transformation of unknown variables. To verify this approach some numerical results obtained by the proposed method are compared with measured ones. © 1993 IEEE

    DOI

  • Physical Meaning of Gauge Conditions in Eddy Current Analysis

    T. Onuki, S. Wakao, T. Yamamura

    IEEE Transactions on Magnetics   29 ( 6 ) 2452 - 2454  1993年

     概要を見る

    There are several ways to define the gauge condition in the A-ϕ method for the 3-D eddy current analysis: e.g. the Coulomb gauge, the Lorentz gauge, etc. Unlike the Coulomb gauge, the physical meaning of the potentials in the Lorentz gauge is not obvious. Therefore this paper introduces a novel physical meaning of the Lorentz gauge, and describes the relationship between these gauge conditions in the A - ϕ method systematically from a physical view-point. © 1993 IEEE

    DOI

  • Novel Boundary Element Analysis for 3-D Eddy Current Problems

    T. Onuki, S. Wakao

    IEEE Transactions on Magnetics   29 ( 2 ) 1520 - 1523  1993年

     概要を見る

    This paper deals with a boundary element method using edge elements for 3-D eddy current problems. In this method the eddy current region is formulated only by means of the electric field intensity E, while the free space only by the magnetic field intensity H. In each region, both unknown variables are independently expressed from each other. By both physical consideration and the appropriate boundary element discretization, these physical quantities can be connected on the interface with ease. To verify this approach some numerical results obtained by the proposed method are compared with measured ones. © 1993 IEEE

    DOI

  • 有限要素・境界要素併用E-H法による三次元渦電流場解析

    電気学会論文誌A   Vol. 112-A, No. 11, pp. 889-89  1992年11月

    DOI

  • 二媒質半無限領域における三次元電磁界問題への有限要素・境界要素併用解析法の適用

    電気学会論文誌A   Vol. 112-A, No. 11, pp. 897-90  1992年11月

    DOI

  • 3D EDDY-CURRENT ANALYSIS BY THE HYBRID FE-BE METHOD USING MAGNETIC-FIELD INTENSITY-H

    T ONUKI, S WAKAO, M SHIMAZAKI

    IEEE TRANSACTIONS ON MAGNETICS   28 ( 5 ) 2259 - 2261  1992年09月

     概要を見る

    This paper describes the hybrid finite element and boundary element method for the electromagnetic problems. To attain good accuracy, we adopt the magnetic field intensity H as much as possible as the physical quantity in the hybrid method. We also propose a new boundary element discretization in the H formulation, which makes it easy to couple the BE region with the FE region by introducing the edge boundary element.
    Some numerical results obtained by the proposed method are compared with measured ones.

    DOI

  • 3次元渦電流場に対する辺要素を用いた有限要素・境界要素結合解法の適用

    日本シミュレーション学会誌   Vol. 11, No. 3, pp. 221-227  1992年09月

  • 渦電流場解析における各種ゲージの物理的意味

    電気学会静止器・回転機合同研究会   SA-92-2, RM-92-37  1992年08月

  • スカラポテンシャルを未知数とする有限要素・境界要素併用法による三次元電磁界解析

    電気学会論文誌A   Vol. 112-A, No. 5, pp. 346-354  1992年05月

    DOI

  • 有限要素・境界要素併用法による三次元動磁界解析

    第8回ソフトウェア コンファレンス   pp. 27-30  1992年03月

  • 三次元渦電流問題に対する辺要素を用いた有限要素・境界要素併用法

    日本シミュレーション学会第13回計算電気・電子工学シンポジウム   pp. 89-94  1992年03月

  • 磁界の強さHを用いた境界要素法による三次元渦電流場の数値解析

    日本シミュレーション学会第13回計算電気・電子工学シンポジウム   pp. 35-40  1992年03月

  • 境界要素法における各種考察物理量に関する比較検討

    平成4年電気学会全国大会   No. 846  1992年03月

  • NOVEL BOUNDARY ELEMENT FORMULATION IN HYBRID FE-BE METHOD FOR ELECTROMAGNETIC-FIELD COMPUTATIONS

    T ONUKI, S WAKAO

    IEEE TRANSACTIONS ON MAGNETICS   28 ( 2 ) 1162 - 1165  1992年03月

     概要を見る

    This paper proposes a novel boundary element formulation using the scalar potential in the hybrid finite element (FE) and boundary element (BE) method for the electromagnetic problems. We adopt the analytical integration as much as possible in this method. This approach has the advantage of reducing the number of unknown variables and makes it easy to couple the BE region with the FE region. Some numerical results obtained by the proposed method are compared with measured ones.

    DOI

  • Investigation of Supplied Currents in Tubular Linear Induction Motor

    Takashi Onuki, Shinji Wakao, Youichi Kasahara

    IEEJ Transactions on Industry Applications   112 ( 12 ) 1179 - 1186  1992年

     概要を見る

    The linear induction motor (LIM) is structurally divided into the flat and the tubular-type. In this paper, we study one kind of tubular linear induction motor which has the primary configuration composed of four pieces of flat-type core. We call this type of motor "the square tubular LIM". The tubular LIM has such a feature that its primary winding is a kind of ring winding, so we can independently supply the primary currents in each slot and hence easily obtain the various winding schemes. Though the square tubular LIM has various merits as stated above, the number of slots is usually limited in conventional applications. In this paper, therefore, we investigate the exciting current scheme with a view to improving primary magneto-motive forces. Firstly we determine the exciting current scheme in unloaded system by using polyphase alternating currents. Secondly we determine another exciting current scheme in loaded system by the hybrid finite element and boundary element method, and the augmented Lagrange multiplier method. Finally we confirm the proposed method by experiment. © 1992, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • 3D Eddy Current Analysis by The Hybrid FE-BE Method using Magnetic Field Intensity H

    T. Onuki, S. Wakao, M. Shimazaki

    IEEE Transactions on Magnetics   28 ( 5 ) 2259 - 2261  1992年

     概要を見る

    This peper describes the hybrid finite element and boundary element method for the electromagnetic problems. To attain good accuracy, we adopt the magnetic field intensity H as much as possible as the physical quantity in the hybrid method. We also propose a new boundary element discretization in the H formulation which makes it easy to couple the BE region with the FE region by introducing the edge boundary element. Some numerical results obtained by the proposed. method are compared with measured ones. © 1992 IEEE

    DOI

  • Novel Boundary Element Formulation in Hybrid FE-BE Method for Electromagnetic Field Computations

    T. Onuki, S. Wakao

    IEEE Transactions on Magnetics   28 ( 2 ) 1162 - 1165  1992年

     概要を見る

    This paper proposes a novel boundary element formulation using the scalar potential in the hybrid finite element (FE) and boundary element (BE) method for the electromagnetic problems. We adopt the analytical integration as much as possible in this method. This approach has the advantage of reducing the number of unknown variables and makes it easy to couple the BE region with the FE region. Some numerical results obtained by the proposed method are compared with measured ones. © 1992 IEEE

    DOI

  • Nonlinear magnetic field analysis using scalar potential in hybrid finite and boundary element method

    Proc. of The 4th Intl. ISEM Symposium   pp. 485-488  1992年01月

  • 角筒型リニア誘導機における推力特性向上を図った一次電流分布の検討

    電気学会論文誌D   112 ( 12 ) 1179 - 1186  1992年

    DOI

  • 境界要素法を用いた各種三次元磁界解析の比較検討

    境界要素法研究会, 境界要素法論文集   Vol. 8, pp. 125-130  1991年12月

  • 磁界の強さHを用いた有限・境界要素併用法による三次元渦電流解析

    電気学会静止器・回転機合同研究会   SA-91-29, RM-91-92  1991年10月

  • Performance determination of linear brushless motor by using hybrid boundary element method and analytical method

    Proc. of Intl. Conf. on the Evolution and Modern Aspects of Synchronous Machines   pp. 1163-1168  1991年08月

  • 直方体有限要素(辺要素)及び長方形境界要素を用いた三次元電磁界解析

    日本シミュレーション学会第12回計算電気・電子工学シンポジウム   pp. 117-122  1991年03月

  • Calculation of electromagnetic forces in magnetic levitation system by 3-D magnetic field analysis

    Proc. of The 3rd Intl. ISEM Symposium   pp. 371-374  1991年01月

  • 磁界の強さHを用いた磁界解析における境界要素形状の考察

    境界要素法研究会, 境界要素法論文集   Vol. 7, pp. 147-152  1990年12月

  • 電磁界問題に対する長方形境界要素及び直方体有限要素を用いた結合解法

    境界要素法研究会, 境界要素法論文集   Vol. 7, pp. 71-76  1990年12月

  • Improved boundary element formulation using scalar potential in hybrid BE-FE method applied to electromagnetic problems

    Proc. of The 12th Intl. Conf. on Boundary Elements in Engineering   pp. 295-305  1990年09月

  • 各種要素を用いた有限・境界要素併用法による数値解析の精度比較

    電気学会静止器・回転機合同研究会   SA-90-29, RM-90-41  1990年08月

  • スカラーポテンシャルを多用した有限・境界要素併用法による電磁界解析

    電気学会静止器・回転機合同研究会   SA-90-30, RM-90-42  1990年08月

  • 有限要素・境界要素併用法による三次元電磁界解析

    早稲田大学情報科学研究教育センター紀要   Vol. 11, 90/spring, pp. 1-14  1990年04月

  • 有限要素・境界要素併用法を用いた電磁界解析

    第6回ソフトウェア コンファレンス   pp. 5-8  1990年03月

  • 有限要素法およびスカラーポテンシャルを用いた境界要素法による三次元電磁界の結合解法

    日本シミュレーション学会第11回計算電気・電子工学シンポジウム   pp. 165-170  1990年03月

  • 2媒質の境界における0-1次境界要素法の接合について

    日本シミュレーション学会第10回計算電気・電子工学シンポジウム   pp. 37-41  1989年03月

  • 永久磁石を用いた電気機器の磁界解析に基づく設計

    電気学会回転機研究会   RM-88-72  1988年11月

▼全件表示

書籍等出版物

  • EE Text 電気エネルギー工学通論

    (株)オーム社  2003年12月

  • 電磁界数値解析における最近の技術動向

    電気学会技術報告  2002年12月

  • 新エネルギー大辞典

    (株)工業調査会  2002年02月

  • 太陽エネルギー利用技術の実用化要件と技術開発の将来

    電気学会技術報告  2000年07月

Misc

  • 41150 既存工業化住宅を用いた改修型ゼロ・エネルギーハウスの提案と実証評価 その3 自立的なエネルギー運用を目指した設備・制御計画

    常岡 優吾, 大木 玲奈, 山口 真吾, 菅野 颯馬, 中川 純, 廣川 由樹, 渡辺 直哉, 小林 達宏, 田辺 新一, 秋元 孝之, 林 泰弘, 若尾 真治

    環境工学II   ( 2018 ) 315 - 316  2018年07月

    CiNii

  • 41151 既存工業化住宅を用いた改修型ゼロ・エネルギーハウス の提案と実証評価 その 4:エネルギー運用に関する冬季実測結果

    大木 玲奈, 常岡 優吾, 山口 真吾, 菅野 颯馬, 中川 純, 廣川 由樹, 渡辺 直哉, 小林 達宏, 田辺 新一, 秋元 孝之, 林 泰弘, 若尾 真治

    環境工学II   ( 2018 ) 317 - 318  2018年07月

    CiNii

  • 電磁界解析の高精度化に残された課題(その2)改良簡易TP-EEC法の検討 (静止器 回転機合同研究会・電磁界数値計算技術とその応用)

    徳増 正, 松下 真琴, 高橋 康人, 藤原 耕二, 若尾 真治

    電気学会研究会資料. RM   2017 ( 16 ) 69 - 74  2017年01月

    CiNii

  • MMAによるレベルセット関数に基づく磁界問題トポロジー最適化手法の収束特性改善 (エレクトロニクスシミュレーション)

    岡本 吉史, 増田 弘, 星野 玲央奈, 若尾 真治

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 212 ) 151 - 156  2016年09月

    CiNii

  • 三次元磁界-熱連成FEM解析と二次元レベルセット法の併用による誘導加熱ロールの一次側鉄心設計に関する検討 (エレクトロニクスシミュレーション)

    廣野 数樹, 星野 玲央奈, 若尾 真治, 岡本 吉史, 田 宇鎭

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 212 ) 161 - 166  2016年09月

    CiNii

  • 電磁界解析の高精度化に残された課題 : 過渡定常解の収束改善法の見直し (エレクトロニクスシミュレーション)

    徳増 正, 松下 真琴, 高橋 康人, 藤原 耕二, 若尾 真治

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 212 ) 133 - 138  2016年09月

    CiNii

  • 局所展開辺要素法を用いた磁界解析に関する基礎的検討 (エレクトロニクスシミュレーション)

    若山 裕綺, 内山 卓也, 若尾 真治, 徳増 正, 髙橋 康人, 藤原 耕二

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 212 ) 121 - 125  2016年09月

    CiNii

  • 空孔感度を導入したレベルセット法による磁気シールドのトポロジー最適化に関する検討 (エレクトロニクスシミュレーション)

    星野 玲央奈, 神谷 剛志, 若尾 真治, 岡本 吉史

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 212 ) 145 - 149  2016年09月

    CiNii

  • MMAによるレベルセット関数に基づく磁界問題トポロジー最適化手法の収束特性改善 (静止器 回転機合同研究会・電磁界数値計算技術,一般)

    岡本 吉史, 増田 弘, 星野 玲央奈, 若尾 真治

    電気学会研究会資料. RM   2016 ( 103 ) 155 - 160  2016年09月

    CiNii

  • 局所展開辺要素法を用いた磁界解析に関する基礎的検討 (静止器 回転機合同研究会・電磁界数値計算技術,一般)

    若山 裕綺, 内山 卓也, 若尾 真治, 徳増 正, 髙橋 康人, 藤原 耕二

    電気学会研究会資料. RM   2016 ( 103 ) 121 - 125  2016年09月

    CiNii

  • 空孔感度を導入したレベルセット法による磁気シールドのトポロジー最適化に関する検討 (静止器 回転機合同研究会・電磁界数値計算技術,一般)

    星野 玲央奈, 神谷 剛志, 若尾 真治, 岡本 吉史

    電気学会研究会資料. RM   2016 ( 103 ) 149 - 153  2016年09月

    CiNii

  • 電磁界解析の高精度化に残された課題 : 過渡定常解の収束改善法の見直し (静止器 回転機合同研究会・電磁界数値計算技術,一般)

    徳増 正, 松下 真琴, 高橋 康人, 藤原 耕二, 若尾 真治

    電気学会研究会資料. RM   2016 ( 103 ) 75 - 80  2016年09月

    CiNii

  • 真電荷密度と電気二重層を未知数とする境界積分方程式による静電界解析 (静止器 回転機合同研究会・電磁界数値計算技術とその応用)

    笠 健悟, 若尾 真治, 髙橋 康人, 石橋 一久, Andjelic Zoran, 藤原 耕二

    電気学会研究会資料. RM   2016 ( 1 ) 43 - 48  2016年01月

    CiNii

  • 磁気二重層法を用いた静磁界磁気シールド解析に関する一考察 (静止器 回転機合同研究会・電磁界数値計算技術とその応用)

    笠 健悟, 吉岡 卓哉, 若尾 真治, 高橋 康人, 石橋 一久, 藤原 耕二

    電気学会研究会資料. RM   2015 ( 25 ) 7 - 11  2015年03月

    CiNii

  • 静磁界問題における境界積分方程式法の多重連結問題への適用に関する一考察 (静止器 回転機合同研究会・電磁界数値計算技術とその応用)

    笠 健悟, 若尾 真治, 高橋 康人, 石橋 一久, 藤原 耕二

    電気学会研究会資料. RM   2014 ( 80 ) 1 - 5  2014年09月

    CiNii

  • 予測・運用・制御の一貫したGEMSの電圧制御とHEMSの電熱運用手法との協調EMS手法の評価 (電力技術 電力系統技術合同研究会・(1)電力技術・電力系統技術一般,(2)分散電源)

    芳澤 信哉, 河野 俊介, 吉田 彬, 藤本 悠, 村田 昇, 若尾 真治, 田辺 新一, 天野 嘉春, 林 泰弘

    電気学会研究会資料. PE   2014 ( 66 ) 63 - 67  2014年09月

    CiNii

  • S0840101 快適性を考慮した家庭用エネルギーシステムの最適運用方策の検討([S084]分散型エネルギーシステム,動力エネルギーシステム部門)

    吉田 彬, 藤本 悠, 村田 昇, 若尾 真治, 田辺 新一, 天野 嘉春

    年次大会 : Mechanical Engineering Congress, Japan   2014   "S0840101 - 1"-"S0840101-5"  2014年09月

     概要を見る

    The main objectives of this study are to consider both thermal comfort and energy consumption on operational planning problem of residential energy system, and to handle uncertainty of energy demand and PV output for the future as a scenario-based stochastic programming problem. The energy system consists of photovoltaic power generator, electrical-driven room air-conditioner and PEM type fuel-cell cogeneration system. We introduce mathematical optimization theory for operational planning problem, because the targeted system has many alternative operations. As a result, the optimal operational planning problem, which is extended by considering PMV and future scenarios as constraints, concludes that the residential energy system achieves 33% of energy saving ratio in the case of 1.0 of PMV.

    CiNii

  • 静磁界問題における境界積分方程式法の解析精度向上に関する一考察 (静止器 回転機合同研究会・電磁界数値計算技術とその応用)

    吉岡 卓哉, 若尾 真治, 高橋 康人, Kielhorn Lars, 石橋 一久, 藤原 耕二

    電気学会研究会資料. RM   2014 ( 1 ) 9 - 14  2014年01月

    CiNii

  • 発電量・負荷量予測情報を活用した太陽光発電システムの蓄電池運用最適化技術 (特集 スマートグリッドと蓄電システム)

    若尾 真治

    スマートグリッド : 技術雑誌 = Smart grid : technical journal   4 ( 1 ) 3 - 8  2014年01月

    CiNii

  • 年/週/日単位の変動特性に基づいた住宅負荷のクラスタ解析

    井内新也, 伊藤友紀, 若尾真治, 藤本悠, 林泰弘, 逢坂哲彌

    電気学会全国大会講演論文集(CD-ROM)   2014  2014年

    J-GLOBAL

  • 磁気回路設計における解の多様性向上のための二段階位相最適化手法

    松林 祐, 永野 拓身, 若尾 真治, 岡本 吉史

    電気学会研究会資料. SA, 静止器研究会   2013 ( 59 ) 23 - 28  2013年09月

    CiNii

  • 不連続ガラーキン有限要素法を用いた3次元磁界解析

    淵野 瑞輝, 松林 祐, 若尾 真治, 徳増 正, 藤田 真史, 高橋 康人, 藤原 耕二

    電気学会研究会資料. SA, 静止器研究会   2013 ( 1 ) 1 - 6  2013年01月

    CiNii

  • 逐次線形計画法による材料密度ベースの位相最適化手法を用いた磁気回路設計

    富永 悠介, 岡本 吉史, 若尾 真治, 里 周二

    電気学会研究会資料. SA, 静止器研究会   2013 ( 1 ) 61 - 66  2013年01月

    CiNii

  • 太陽光発電システムの発電予測に関する技術動向

    大関 崇, 島陰 豊成, 桶 真一郎, 河本 薫, 小林 智尚, 前島 聡, 舟橋 俊久, 若尾 真治

    電気学会研究会資料. FTE, 新エネルギー・環境研究会   2012 ( 38 ) 23 - 29  2012年11月

    CiNii

  • 太陽光発電システムの出力変動特性把握に関する技術動向

    島陰 豊成, 大関 崇, 前島 聡, 桶 真一郎, 河本 薫, 小林 智尚, 舟橋 俊久, 若尾 真治

    電気学会研究会資料. FTE, 新エネルギー・環境研究会   2012 ( 38 ) 15 - 22  2012年11月

    CiNii

  • 密度法を用いた位相最適化における並列計算を援用した大域的最適解の効率的探索方法の提案

    永野 拓身, 安川 昇吾, 若尾 真治, 岡本 吉史

    電気学会研究会資料. RM, 回転機研究会   2012 ( 94 ) 1 - 6  2012年09月

    CiNii

  • Magnetostatic Analysis by Magnetic Moment Method with Surface Loop Current as State Variable (特集 The 20th MAGDA Conference in Pacific Asia (MAGDA2011))

    ISHIBASHI Kazuhisa, ANDJELIC Zoran, TAKAHASHI Yasuhito, Kenta TSUZAKI, Shinji WAKAO, Koji FUJIWARA, Yoshiyuki ISHIHARA

    日本AEM学会誌 = Journal of the Japan Society of Applied Electromagnetics   20 ( 2 ) 366 - 371  2012年06月

     概要を見る

    We have the surface and volume integral equation approaches (SIEA and VIEA) to formulate the electromagnetic fields and adopt VIEA for the magnetostatic analysis by the magnetic moment method (MMM). Even if the MMM employs the volume integral equation, we can solve efficiently the problems by utilizing the fast multipole method. The VIEA replaces magnetic materials with magnetization. When the constant volume element is adopted in discretizaion, the magnetization is regarded equivalently as a surface magnetic charge on the volume element. Utilizing Ampere's law that relates the magnetization with equivalent currents, we introduce a surface loop current for the surface charge. In order to check the adequacy of the proposed MMM with the surface loop current as state variable, we solve typical magnetostatic problems and compare the computed results with those by the conventional MMM.

    CiNii

  • 並列計算を援用した多段式進化型アルゴリズムによる永久磁石型同期電動機の位相最適化計算

    岡本 吉史, 富永 悠介, 若尾 真治, 里 周二

    電気学会研究会資料. SA, 静止器研究会   2012 ( 23 ) 41 - 46  2012年01月

    CiNii

  • 不連続ガラーキン有限要素を用いた磁界解析に関する基礎的検討

    杉本 真都, 若尾 真治, 徳増 正, 藤田 真史, 高橋 康人, 藤原 耕二, 石原 好之

    電気学会研究会資料. RM, 回転機研究会   2012 ( 1 ) 1 - 5  2012年01月

    CiNii

  • ループ電流の二重性を利用する境界積分方程式による静磁界解析

    石橋 一久, ANDJELIC Zoran, 高橋 康人, 藤原 耕二, 石原 好之, 津崎 賢大, 若尾 真治

    電気学会研究会資料. RM, 回転機研究会   2012 ( 1 ) 65 - 70  2012年01月

    CiNii

  • 無限辺要素法を用いた磁界解析における精度検証

    津崎 賢大, 多和田 義大, 若尾 真治, 亀有 昭久, 徳増 正, 高橋 康人, 五十嵐 一, 藤原 耕二, 石原 好之

    電気学会研究会資料. SA, 静止器研究会   2012 ( 1 ) 7 - 12  2012年01月

    CiNii

  • 時間領域並列化有限要素法を用いた誘導機の高速電磁界解析

    高橋 康人, 徳増 正, 藤田 真史, 岩下 武史, 若尾 真治, 藤原 耕二, 石原 好之

    電気学会研究会資料. RM, 回転機研究会   2012 ( 1 ) 31 - 36  2012年01月

    CiNii

  • JITモデリングによる太陽光発電量予測とその信頼性評価

    沈浩洋, 日野英逸, 村田昇, 若尾真治

    研究報告数理モデル化と問題解決(MPS)   2011 ( 14 ) 1 - 6  2011年11月

     概要を見る

    近年,エネルギー問題を解決するための新エネルギー技術が急速に発展している.その一つである太陽光発電システム (PV システム) は,クリーンで限りないエネルギーを利用できるという特徴から注目を集めており,実用化も進んでいる.一方,PV システムは天候に左右されやすく,出力が不安定という問題点を有する.急激な天気の変化により,PV システムによる発電量は短時間に大きく変動し,その予測は困難であることが知られている.本研究では,Just-in-time(JIT) モデリングにより PV システムの発電量予測モデルを構築し,その予測の信頼性尺度として Shannon 情報量を利用することを提案する.提案手法により,次の時刻の発電量予測値が信頼できるかどうかを事前に判断することが可能となり,急激な出力変化への対策を講じることが可能となる.本稿では,実験システムを用いて取得した太陽光発電データを用い,提案手法の有効性を検討した結果を報告する.Recently, remarkable developments of new energy technologies have been achieved against various energy problems. Photovoltaic (PV) system, one of such technologies, has an advantage of utilizing infinite and clean energy. On the contrary, it also has a disadvantage of unreliable power supply mainly caused by unstable weather. The fluctuation of the power supply of PV systems are considerably large because of rapid insulation changes and rapid weather changes, and in some cases, it seems impossible to realize high-accuracy prediction even with sophisticated prediction models. In this study, using a recently proposed estimator for the Shannon information content, a method to output a measure of credibility for prediction is proposed. With the proposed method, it is possible to judge whether the energy supply at a certain future time is unpredictably fluctuate compared to the current value or not, and it is possible to take measures against the rapid change of solar energy generation in advance. From an experimental result using solar energy supply data, we see that the proposed measure of credibility reflects the difficulty of the prediction solar energy supply.

    CiNii

  • JITモデリングによる太陽光発電量予測とその信頼性評価

    沈浩洋, 日野英逸, 村田昇, 若尾真治

    研究報告バイオ情報学(BIO)   2011 ( 14 ) 1 - 6  2011年11月

     概要を見る

    近年,エネルギー問題を解決するための新エネルギー技術が急速に発展している.その一つである太陽光発電システム (PV システム) は,クリーンで限りないエネルギーを利用できるという特徴から注目を集めており,実用化も進んでいる.一方,PV システムは天候に左右されやすく,出力が不安定という問題点を有する.急激な天気の変化により,PV システムによる発電量は短時間に大きく変動し,その予測は困難であることが知られている.本研究では,Just-in-time(JIT) モデリングにより PV システムの発電量予測モデルを構築し,その予測の信頼性尺度として Shannon 情報量を利用することを提案する.提案手法により,次の時刻の発電量予測値が信頼できるかどうかを事前に判断することが可能となり,急激な出力変化への対策を講じることが可能となる.本稿では,実験システムを用いて取得した太陽光発電データを用い,提案手法の有効性を検討した結果を報告する.Recently, remarkable developments of new energy technologies have been achieved against various energy problems. Photovoltaic (PV) system, one of such technologies, has an advantage of utilizing infinite and clean energy. On the contrary, it also has a disadvantage of unreliable power supply mainly caused by unstable weather. The fluctuation of the power supply of PV systems are considerably large because of rapid insulation changes and rapid weather changes, and in some cases, it seems impossible to realize high-accuracy prediction even with sophisticated prediction models. In this study, using a recently proposed estimator for the Shannon information content, a method to output a measure of credibility for prediction is proposed. With the proposed method, it is possible to judge whether the energy supply at a certain future time is unpredictably fluctuate compared to the current value or not, and it is possible to take measures against the rapid change of solar energy generation in advance. From an experimental result using solar energy supply data, we see that the proposed measure of credibility reflects the difficulty of the prediction solar energy supply.

    CiNii

  • Just-In-Time Modeling を用いた日射量予測における信頼度推定

    寺園 隆宏, 若尾 真治, 沈 浩洋, 日野 英逸, 村田 昇

    電気学会研究会資料. MES, メタボリズム社会・環境システム研究会 = The papers of Technical Meeting on Metabolism Society and Environmental Systems, IEE Japan   2011 ( 15 ) 37 - 42  2011年11月

    CiNii

  • 発電量および負荷量予測を利用したPVシステムにおける蓄電池運用法の多目的評価

    林 尚芳, 若尾 真治

    電気学会研究会資料. MES, メタボリズム社会・環境システム研究会 = The papers of Technical Meeting on Metabolism Society and Environmental Systems, IEE Japan   2011 ( 15 ) 43 - 48  2011年11月

    CiNii

  • 表面ループ電流を状態変数とする磁気モーメント法による静磁界解析

    石橋 一久, ANDJELIC Z., 高橋 康人, 藤原 耕二, 石原 好之, 津崎 賢大, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2011 ( 46 ) 79 - 84  2011年08月

    CiNii

  • Just-In-Time Modeling に基づく日射量予測手法の開発

    鈴木 孝宜, 後藤 悠介, 寺園 隆宏, 若尾 真治, 大関 崇

    電気学会研究会資料. MES, メタボリズム社会・環境システム研究会 = The papers of Technical Meeting on Metabolism Society and Environmental Systems, IEE Japan   2011 ( 1 ) 55 - 61  2011年01月

    CiNii

  • 境界要素法による非線形静磁界解析時の等価体積磁荷の算出法

    石橋 一久, ANDJELIC Zoran, 高松 智明, 若尾 真治, 高橋 康人, 藤原 耕二, 石原 好之

    電気学会研究会資料. RM, 回転機研究会   2011 ( 1 ) 31 - 36  2011年01月

    CiNii

  • 磁気二重層ポテンシャルによる境界積分方程式を用いるエッジやコーナー部の静磁界解析

    石橋 一久, ANDJELIC Zoran, 若尾 真治, 高松 智明, 高橋 康人, 藤原 耕二, 石原 好之, 藤野 清次

    電気学会研究会資料. RM, 回転機研究会   2010 ( 101 ) 13 - 18  2010年09月

    CiNii

  • 辺要素無限要素法を用いた三次元磁界解析

    民谷 智史, 高松 智明, 若尾 真治, 亀有 昭久, 高橋 康人, 藤原 耕二, 石原 好之

    電気学会研究会資料. RM, 回転機研究会   2010 ( 85 ) 39 - 44  2010年09月

    CiNii

  • 電気機器の過渡磁界解析におけるTDC法およびTP-EEC法の検討

    高橋 康人, 徳増 正, 藤田 真史, 若尾 真治, 藤原 耕二, 石原 好之

    電気学会研究会資料. RM, 回転機研究会   2010 ( 85 ) 83 - 88  2010年09月

    CiNii

  • PVシステム大量導入地域におけるEVバッテリーと据置蓄電池の運用に関する基礎的検討

    木下 真吾, 下尾 高廣, 若尾 真治

    電気学会研究会資料. FTE, 新エネルギー・環境研究会   2010 ( 29 ) 1 - 6  2010年08月

    CiNii

  • 蓄電池容量最小化と適正電圧維持を目的とした風力発電出力平滑化

    上村 浩俊, 酒井 重和, 林 泰弘, 川崎 章司, 松木 純也, 若尾 真治

    電気学会研究会資料. PE, 電力技術研究会   2010 ( 11 ) 83 - 87  2010年03月

    CiNii

  • ATC軌道回路における土木構造物中の鉄筋も考慮した接地導体の誘導妨害電圧低減効果

    山口 大介, 若尾 真治, 奥谷 民雄, 舘 裕

    電気学会研究会資料. PHS, フィジカルセンサ研究会   2010 ( 1 ) 21 - 27  2010年02月

    CiNii

  • ロバスト性を考慮した車軸検知装置の最適化設計

    大竹 飛鳥, 高安 健太, 若尾 真治, 奥谷 民雄, 斉藤 匡彦, 豊田 明久, 高橋 康人

    電気学会研究会資料. RM, 回転機研究会   2010 ( 1 ) 127 - 132  2010年01月

    CiNii

  • 大規模メッシュモデルのためのメッシュモーフィング手法の提案

    三輪 將彦, たに 浩司, 山田 隆, 若尾 真治

    電気学会研究会資料. RM, 回転機研究会   2010 ( 1 ) 25 - 30  2010年01月

    CiNii

  • 統計的パターン認識を用いた分光放射照度の波長重心推定に関する基礎的検討

    飯嶋 彩, 若尾 真治, 川崎 憲広

    太陽/風力エネルギー講演論文集   2010   347 - 350  2010年

    CiNii

  • Just-In-Time Modeling を用いた翌日日射量予測の高精度化に関する基礎的検討

    鈴木 孝宣, 若尾 真治

    電気学会研究会資料. FTE, 新エネルギー・環境研究会   2009 ( 55 ) 25 - 30  2009年12月

    CiNii

  • 蓄電池併設型太陽光発電のシステム設計における多目的評価方法の検討

    下尾 高廣, 佐藤 勝則, 若尾 真治

    電気学会研究会資料. FTE, 新エネルギー・環境研究会   2009 ( 55 ) 1 - 6  2009年12月

    CiNii

  • SD-EEC法を適用したタービン発電機鉄心端部構造物の渦電流解析

    藤田 真史, 上田 隆司, 徳増 正, 垣内 幹雄, 大高 徹, 貝森 弘行, 亀有 昭久, 高橋 康人, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2009 ( 69 ) 33 - 38  2009年09月

    CiNii

  • 回転機の電磁界解析における並列化時間周期有限要素法の有効性に関する検討

    高橋 康人, 岩下 武史, 徳増 正, 藤田 真史, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2009 ( 69 ) 17 - 22  2009年09月

    CiNii

  • 自然エネルギー利用型分散型電源と配電ネットワークとの協調運用形態の検証実験

    酒井 重和, 林 泰弘, 川崎 章司, 松木 純也, 馬場 旬平, 横山 明彦, 北條 昌秀, 若尾 真治, 森 健二郎, 不破 由晃

    電気学会研究会資料. PE, 電力技術研究会   2009 ( 160 ) 37 - 42  2009年09月

    CiNii

  • 蓄電池容量最小化を目的とした風力発電出力の最適平滑化時定数の決定

    上村 浩俊, 酒井 重和, 林 泰弘, 川崎 章司, 松木 純也, 若尾 真治

    電気学会研究会資料. PE, 電力技術研究会   2009 ( 160 ) 49 - 53  2009年09月

    CiNii

  • 接地導体を用いたATC軌道回路における誘導妨害電圧の低減法に関する一考察

    山口 大介, 若尾 真治, 奥谷 民雄, 舘 裕

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2009 ( 32 ) 1 - 7  2009年07月

    CiNii

  • ATC軌道回路における誘導妨害電圧の低減法に関する基礎的検討

    孫 佳男, 山口 大介, 若尾 真治, 奥谷 民雄, 舘 裕

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2009 ( 16 ) 17 - 22  2009年05月

    CiNii

  • 多変量回帰的スプライン(MARS)を用いた応答曲面近似法の電気機器設計への適用に関する基礎的検討

    高安 健太, 大竹 飛鳥, 三輪 將彦, 若尾 真治, 高橋 康人

    電気学会研究会資料. SA, 静止器研究会   2009 ( 1 ) 81 - 86  2009年01月

    CiNii

  • 積層構造を有する電気機器の大規模電磁界解析における代数マルチグリッド法の評価

    三輪 將彦, 仙波 和樹, 山田 隆, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2009 ( 1 ) 63 - 68  2009年01月

    CiNii

  • IDR定理に基づくIDR(s)反復解法族の電磁界問題への適用と評価

    藤野 清次, 尾上 勇介, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2009 ( 1 ) 53 - 58  2009年01月

    CiNii

  • 直方体要素用高速多重極法によるマイクロマグネティックス計算の高速化

    高橋 康人, 岩下 武史, 金澤 正憲, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2009 ( 1 ) 41 - 46  2009年01月

    CiNii

  • Verification Experiment of Determination Method of Optimal Smoothing Time Constant of Wind Power Generation System with Storage Battery

    S.Sakai, Y.Hayashi, S.Kawasaki, J.Matuki, H.Kamimura, S.Wakao

    Proceedings of the International Conference on Electrical Engineering 2009    2009年

  • 電磁界数値解析におけるIDR(s)法の有効性評価

    高橋 康人, 岩下 武史, 金澤 正憲, 若尾 真治

    情報処理学会研究報告. EVA, [システム評価]   2008 ( 119 ) 1 - 6  2008年11月

     概要を見る

    電磁界数値解析に基づく電気機器設計の高度化のためには,さまざまな数値解析手法の特長を活かし,対象に応じて使い分けることが重要だと考えられる。しかし,積分方程式法などいくつかの数値解析手法は,非対称な係数行列を扱わなければならない難点がある。近年,双直交条件に基づくBiCG法系統の反復法や,最小条件に基づくGMRES法とはまったく異なるクリロフ部分空間法であるIDR(s)法が提案され,さまざまな分野においてその性能評価が進められているが,電磁界数値解析分野においてはその有効性について不明な点も残されている。そこで本稿では,非対称マトリクスを扱う電磁界数値解析手法を対象として,従来用いられているGMRES(k)法やBiCGSTAB2法との比較を行い,IDR(s)法の有効性を検証する。

    CiNii

  • 多線条回路網解析における端効果考慮法の基礎的検討

    山口 大介, 孫 佳男, 若尾 真治, 奥谷 民雄, 舘 裕, 稲田 聡

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2008 ( 44 ) 27 - 31  2008年11月

    CiNii

  • ANSWERを用いた分散型電源と配電ネットワークの協調運用形態の検証実験

    酒井 重和, 林 泰弘, 川崎 章司, 松木 純也, 馬場 旬平, 横山 明彦, 北條 昌秀, 若尾 真治, 森 健二郎, 不破 由晃

    電気学会研究会資料. PE, 電力技術研究会   2008 ( 21 ) 1 - 6  2008年08月

    CiNii

  • ディーゼルハイブリッド鉄道車両の燃料消費量と排出ガス削減を目的としたエンジン運転パターンの最適化

    小川 知行, 吉原 博昭, 若尾 真治, 近藤 圭一郎, 近藤 稔

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2007 ( 42 ) 1 - 6  2007年11月

    CiNii

  • 代数マルチグリッド法を前処理としたCG法の電磁界解析における実用性に関する考察

    三輪 將彦, 山田 隆, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2007 ( 54 ) 25 - 30  2007年09月

    CiNii

  • マイクロマグネティックスの反磁界計算におけるFMMおよびACAの導入

    高橋 康人, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2007 ( 54 ) 73 - 78  2007年09月

    CiNii

  • Compumag 2007 会議報告

    藤原 耕二, 亀有 昭久, 若尾 真治, 高橋 康人, 五十嵐 一, 松尾 哲司, 岩下 武史, 村松 和弘, 岡本 吉史, 山田 隆, 河瀬 順洋, 山崎 克巳, 平田 勝弘

    電気学会研究会資料. SA, 静止器研究会   2007 ( 54 ) 91 - 97  2007年09月

    CiNii

  • 電気機器設計のための高速大規模電磁界数値解析

    高橋 康人, 若尾 真治

    計算数理工学レビュー   2007 ( 2 ) 1 - 15  2007年09月

    CiNii

  • 「電磁界数値解析技術とその応用」特集号によせて

    若尾 真治

    電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society   127 ( 8 ) 877 - 877  2007年08月

    CiNii

  • 配電ネットワーク模擬実験による分散型電源と配電ネットワークとの協調運用形態の検証

    酒井 重和, 林 泰弘, 川崎 章司, 松木 純也, 吉川 尚志, 馬場 旬平, 横山 明彦, 北條 昌秀, 若尾 真治, 小林 直樹, 生石 光平

    電気学会研究会資料. PE, 電力技術研究会   2007 ( 29 ) 13 - 18  2007年07月

    CiNii

  • 新幹線高架橋での電磁誘導測定試験と解析

    孫 佳男, 小川 知行, 若尾 真治, 奥谷 民雄, 中村 信幸, 寺田 夏樹, 館 裕, 稲田 聡

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2007 ( 23 ) 15 - 22  2007年07月

    CiNii

  • 動的計画法によるディーゼルハイブリッド鉄道車両の燃料消費量特性

    吉原 博昭, 小川 知行, 若尾 真治, 近藤 圭一郎, 近藤 稔

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2007 ( 23 ) 23 - 28  2007年07月

    CiNii

  • 配電系統模擬実験による分散型電源と配電系統との協調運用形態の検証

    林 泰弘, 川崎 章司, 松木 純也, 酒井 重和, 野村 知弘, 馬場 旬平, 横山 明彦, 北條 昌秀, 若尾 真治, 小林 直樹, 生石 光平

    電気学会研究会資料. PE, 電力技術研究会   2007 ( 1 ) 11 - 20  2007年03月

    CiNii

  • 実規模電磁界解析のための数値計算技術調査専門委員会

    若尾 真治

    電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society   127 ( 3 ) 547 - 547  2007年03月

    CiNii

  • ハイブリッド電源鉄道車両における動的計画法を用いた最適電力制御法の検討

    小川 知行, 吉原 博昭, 若尾 真治, 近藤 圭一郎, 近藤 稔

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2007 ( 1 ) 11 - 18  2007年02月

    CiNii

  • 均質化法を用いた三次元有限要素法による永久磁石同期電動機の損失解析

    川岸 賢二, 高橋 康人, 若尾 真治, 近藤 稔, 寺内 伸雄

    電気学会研究会資料. SA, 静止器研究会   2007 ( 17 ) 25 - 30  2007年01月

    CiNii

  • 電流ベクトルポテンシャル法によるコイル電流分布導出に関する一考察

    高橋 康人, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2007 ( 1 ) 25 - 30  2007年01月

    CiNii

  • 感度解析手法とシグマレベル評価を併用したロバスト最適化手法に関する基礎的検討

    西田 直樹, 高橋 康人, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2007 ( 1 ) 31 - 36  2007年01月

    CiNii

  • 鉄道車両駆動用永久磁石同期電動機の回転角速度センサレス制御に関する考察 : シンプルかつ高性能な制御システム

    近藤 圭一郎, 米山 崇, 谷口 峻, 望月 伸亮, 若尾 真治

    電気学会研究会資料. SPC, 半導体電力変換研究会   2006 ( 178 ) 37 - 42  2006年12月

    CiNii

  • 高次方形波電圧重畳によるPMSM低速域位置センサレス制御

    谷口 峻, 若尾 真治, 近藤 圭一郎, 米山 崇

    電気学会研究会資料. SPC, 半導体電力変換研究会   2006 ( 147 ) 1 - 7  2006年11月

    CiNii

  • 高架橋の電磁遮蔽効果を考慮した誘導予測計算法の提案(2)

    三枝 雄一郎, 小川 知行, 孫 佳男, 若尾 真治, 奥谷 民雄, 中村 信幸, 寺田 夏樹, 館 裕, 稲田 聡

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2006 ( 83 ) 27 - 33  2006年11月

    CiNii

  • 幾何マルチグリッド法におけるスムーザーに関する考察

    三輪 將彦, 西尾 隆行, 山田 隆, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2006 ( 58 ) 43 - 48  2006年08月

    CiNii

  • 配電系統模擬実験設備を用いた分散型電源の連系可能最大出力の計測実験

    酒井 重和, 林 泰弘, 松木 純也, 川崎 章司, 野村 知弘, 馬場 旬平, 横山 明彦, 北條 昌秀, 若尾 真治, 小林 直樹, 生石 光平

    電気学会研究会資料. PE, 電力技術研究会   2006 ( 85 ) 7 - 11  2006年08月

    CiNii

  • Large-scale analysis of eddy-cuffent problems by the hybrid finite element-boundary element method combined with the fast multipole method (vol 42, pg 671, 2006)

    Yasuhito Takahashi, Shinji Wakao

    IEEE TRANSACTIONS ON MAGNETICS   42 ( 8 ) 2110 - 2110  2006年08月

    その他  

    DOI

  • 遠い子孫のために

    若尾 真治

    太陽エネルギー = Solar energy   32 ( 4 ) 1 - 1  2006年07月

    CiNii

  • ハイブリッド鉄道車両による所要時間短縮効果と消費電力量低減効果のトレードオフ関係に関する検討

    吉原 博昭, 小川 知行, 若尾 真治, 近藤 圭一郎

    電気学会研究会資料. TER, 交通・電気鉄道研究会   2006 ( 48 ) 49 - 54  2006年07月

    CiNii

  • 電磁界解析における高速大規模数値計算技術

    亀有昭久, 五十嵐一, 若尾真治, 野口聡, 池田文昭, 石橋一久, 榎園正人, 遠藤久, 大場彰人, 金井靖, 金山寛, 神谷淳, 河本正, 久保武春, 結石友宏, 島崎真昭, かん浩司, 坪井始, 徳増正, 徳良晋, 西口磯春, 羽野光夫, 房安浩嗣, 藤原耕二, 本間利久, 松田哲也, 松原克夫, 村松和弘, 宮田健治, 森田克明, 山下英生, 黄こう宇, 松尾哲司, 美船健, 山田隆, 岩下武史, 島田茂樹, 大神光司, 浜田昌司, 瀬島紀夫

    電気学会技術報告   ( 1043 ) 120P  2006年01月

    J-GLOBAL

  • 鉄道車両駆動用永久磁石同期電動機の回転子設計

    近藤 稔, 近藤 圭一郎, 藤島 寧, 若尾 真治

    電気学会研究会資料. SA, 静止器研究会   2004 ( 14 ) 19 - 24  2004年01月

    CiNii

▼全件表示

受賞

  • 電気学会学術振興賞・論文賞

    2008年05月  

共同研究・競争的資金等の研究課題

  • 太陽光発電集中連系配電ネットワークにおける日射予測を用いた蓄エネ制御支援手法開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(挑戦的萌芽研究)

    研究期間:

    2013年
    -
    2016年
     

  • 次世代重粒子線がん治療装置用超伝導加速器の基盤技術開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(A))

    研究期間:

    2011年
    -
    2014年
     

  • 太陽光発電大量連系を可能とする次世代配電ネットワーク運用支援統合シミュレータ開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2011年
    -
    2014年
     

  • 普及型重粒子線癌治療装置用超伝導コイルシステム開発のための基礎的研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2008年
    -
    2011年
     

  • 電気機器省エネルギー設計への応用へ向けた高速高精度電磁界数値解析技術の実用化研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(C))

    研究期間:

    2008年
    -
    2011年
     

  • 広域災害に対するインテリジェント太陽光発電システムの開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(若手研究(B))

    研究期間:

    2003年
    -
    2005年
     

  • バルク超伝導体の特性評価と応用のための基礎的研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2001年
    -
    2004年
     

  • 光ネットワーク終端機器に対する太陽光無停電電源システムの研究開発プロジェクト

    文部科学省 

    研究期間:

    1999年
    -
    2003年
     

  • 新構成の角棒状リニアハイブリッドモータの開発とその実用化に関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(C))

    研究期間:

    1999年
    -
    2001年
     

  • 電磁界数値解析による高齢者用医療機器システムの最適設計および実用化に関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(奨励研究(A))

    研究期間:

    1999年
    -
    2001年
     

  • 太陽光自立電源システムの開発研究

    文部科学省 

    研究期間:

    1997年
    -
    2001年
     

  • アドバンスト発電システムに関する研究

    文部科学省 

    研究期間:

    1997年
    -
    2001年
     

  • 交流用超伝導ケーブル導体の安定性向上と応用のための基礎的研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    1997年
    -
    2000年
     

  • 永久磁石を用いた分割磁極型同期モータの実用化に関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(C))

    研究期間:

    1997年
    -
    1999年
     

  • 電磁界数値解析と数理計画法との併用による電気機器の最適設計法の開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(奨励研究(A))

    研究期間:

    1997年
    -
    1999年
     

  • 超伝導ケーブル導体の過渡安定性に関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(一般研究(B))

    研究期間:

    1994年
    -
    1997年
     

  • 有限要素法および境界要素法を用いた電気機器における電磁力解析手法の開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(一般研究(C))

    研究期間:

    1994年
    -
    1997年
     

  • 有限要素法と境界要素法の併用法による導体運動を伴う渦電流場の三次元解析

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(奨励研究(A))

    研究期間:

    1994年
    -
    1995年
     

▼全件表示

特定課題研究

  • マルチフィジックス実規模機器設計における高速トポロジー最適化システムの構築

    2018年  

     概要を見る

    電磁エネルギー変換における大幅な高効率化を実現すべく、磁気回路のトポロジー最適化の高速化に向けた情報処理技術の適用検討を行った。具体的には、画像認識分野で著しい性能を発揮している畳み込みニューラルネットワーク(CNN)を用いた分類器を開発し、磁性体分布を入力に、ターゲット領域の磁気エネルギーのレベルを出力とし、分類精度向上の検討を行った。CNNにおける学習データと内部パラメータが分類精度に与える影響等の考察に加え、学習データの正解ベクトルを確率的に分割する手法を提案し、分類精度の向上を達成した。今後は、様々な実規模磁気回路の最適化設計を対象に、開発分類器の効果的な適用法の検討を行う予定である。

  • 太陽光発電出力予測の信頼性評価導入による汎化性能を備えた配電系統シミュレータ開発

    2014年  

     概要を見る

    近年、環境エネルギー問題を背景に、太陽光発電(PV)の電力系統への大量導入が推進されている。一方、PVシステムの出力は日射量に依存して大きく変動するため、PV余剰電力の逆潮流に伴う系統周波数変動問題など、電力系統における電力品質の劣化も懸念されている。このような問題への対策として、本研究ではJIT Modelingを用いた日射量予測信頼区間の推定方法を提案し、開発手法を用いることで太陽光発電出力予測を十分な精度で確率的に評価することが可能であることを明らかにした。本研究成果は、今後のPV大量導入を見据えた際に、より有効なエネルギーマネジメントの実現に資する有益な情報を提供しうると考えられる。

  • 電磁界数値解析による機器最適化設計技術の高度化

    2004年  

     概要を見る

    機器の開発期間やコストを削減するためには、計算機を用いた最適化設計法の適用が極めて有効であると考えられるが、その普及率はいまだに期待の域には達していない。その主な理由の一つとして、実用的観点から判断したときの最適解の品質にまだ多くの問題点が残されていることが挙げられる。例えば、現場が抱えている複雑な非線形問題に対して反復計算を基本とする最適化設計法を適用した場合、計算精度を実用十分なレベルに保持しようとすれば、工学的に許容できる計算時間の範囲内で最適解を得ることが困難となる場合が多い。さらに、計算によって得られた情報を基に設計者が最終的な設計パラメータを決定する際、従来の最適化設計法では単一の最適解が示されるのみで、各設計変数が評価関数値に及ぼす影響なども不明確である場合が多く、設計者にとって十分な情報が得られているかは疑問の余地が残る。このような背景のもと、先に述べた難点に対する一つの解決策として、本研究では電気機器の最適化設計問題を対象に応答曲面近似法(RSM: Response Surface Methodology)の導入・実用化を試みた。RSMを導入する最大の利点の一つは、最適化計算の高速化である。RSMを導入すれば、最適化の反復計算過程で必要となる評価関数値を、設計変数の多項式表現による近似式(応答曲面)から算出することが可能となる。したがって、最適化計算の反復過程に費やす計算時間を大幅に削減することが可能である。さらに、評価関数が設計変数を用いた応答曲面近似式で表現されるので、設計空間における評価関数値の応答傾向を容易に把握することができ、設計者にとって有用な情報を多く得ることができる。一般に電気機器の最適化設計の特性として、設計変数の個数が多く、またそれぞれの設計空間(設計変数の変域)が広大であることが多い。また、特に回転機の場合、磁性材料の強い非線形現象を伴う。これらの結果、高精度な応答曲面近似式を導出することは極めて困難なものとなる。したがって、RSMを導入して最適化計算の高速化を図るにあたり、いかに低い計算コストで高精度な応答曲面近似式を算出するかが最も重要な点となる。従来、少ない回数の有限要素解析で高精度な近似式を算出する目的で、直交表を用いる実験計画法(DOE)を導入する報告があるが、多くの場合、設計変数が少なく、また低次の多項式で十分に評価関数を近似できるような簡単な問題に限られている。しかし、先に述べた特徴を有する回転機最適化設計では、近似式に高次の多項式を導入する必要がある。さらに、直交表を用いてDOEを行う際に、多変数、多水準において交互作用を考慮する必要があり、直交表への割り付けに多くの手間を要する。この難点を打開するために、本研究では計算機支援のDOEを開発した。また、より高精度な応答曲面近似式を算出する目的で、まず全体の設計空間で応答曲面の概形を得ておき、その情報をもとに最適解候補点周囲の領域に設計空間を段階的に狭めて、近似精度を向上させていく手法を提案した。提案手法の妥当性・有効性を確認するために、電気機器の最適化設計の一例として次世代鉄道車両駆動用電動機として注目されているアウターロータ型永久磁石同期電動機を取り上げ、低い計算コストで十分な精度の応答曲面近似式が作成可能であることを確認すると同時に、RSMを導入しない場合と比較して、十分な最適化計算の高速化を達成しつつ、同等以上の最適解が得られることを実証した。さらに、回転機の多目的最適化問題に対しても提案手法を展開し、実機レベルの最適化設計に本手法が十分有効であることを示した。

  • 広域災害時に対する太陽光無停電電源システムの実用化

    2002年   岩本 伸一, 石山 敦士

     概要を見る

     高効率な太陽光発電(PV)システムの開発にあたっては、太陽電池や蓄電池などの構成要素の容量配分や、蓄電池充放電制御における充電開始蓄電池電圧などの様々なシステムパラメータを適切に決定しなければならない。しかし、その決定に必要なデータの収集には、長期間にわたる実験を要するため、すべてのパラメータの変動がシステムに与える影響をあらゆるパターンについて定量的に評価し、最適なパラメータを決定するのは困難である。そこで、効率よくシステム評価する手段として数値シミュレーションの導入が有効であると考えられる。数値シミュレーションは過去に蓄積された気象データを利用してパラメータの様々な組合せのもとで極めて短時間にシステム動作の解析ができ、その解析精度が高ければ高いほど太陽光発電システムの設計開発が高度化できる。このような背景のもと、本研究では、蓄電池を備えた太陽光発電システムの挙動を模擬する数値シミュレータの高精度化に関して重点的に検討を行った。特に、蓄電池充放電特性の新たなモデル式を導入することにより、高精度化の達成を試みた。ここで、蓄電池充放電特性に着目した理由として、太陽光発電システムにおいては蓄電池電圧がPVアレイの切り離しや系統連系などのシステム動作制御の基準となる重要な物理量であり、ひいては、蓄電池充放電特性のモデル化が数値シミュレータの精度を左右することが挙げられる。また従来から蓄電池充放電特性のモデル化は困難であることがよく知られている。本研究では蓄電池充放電特性の新しいモデル式として、充電電流値、および複数の係数を用いて対数関数により記述するモデル式を提案した。このモデル式により、様々な充電電流値の変化に応じた蓄電池電圧の変動を精度よく表現することが可能となった。また、蓄電池は残存容量がある値を超えると蓄電池電圧が急激に上昇することが知られており、この蓄電池電圧上昇率の変化点も係数を用いて記述されている。さらに、これらのモデル式内係数をいかにして決定するかが重要になるが、本研究では遺伝的アルゴリズムにより蓄電池電圧の計算誤差率が極力小さくなるように決定する手法を開発し、数値シミュレータの高精度化を実現した。その際、モデル式内係数の時間的変動が蓄電池の劣化状態を把握する指標となり得ることも、新たに見出した。また、検証用の例題として、広域災害時に対する太陽光無停電電源システムを取り上げ、提案手法の妥当性と有効性も確認した。 以上の成果は、従来の太陽光発電システムの設計方法とは異なる新たな有効なアプローチを提案したものであり、他の様々な種類の太陽光発電システムの設計においても、十分に有効なものと考えられる。

  • 光ネットワーク終端機器に対する太陽光無停電電源システムの実用化に関する研究

    2000年   小貫 天, 田 宇鎮

     概要を見る

     情報化時代に向けて情報通信網は光ファイバケーブルに置き換えられつつあるが、この際、通信網の随所に配置されるケーブル終端用光通信機器や通信端末装置等への電源供給系の信頼性が近年特に重要視されている。銅ケーブルの場合には電話局の高信頼な電源装置からケーブルを介して給電できるが、光ファイバではこれが不可能となり、商用配電系統からの給電に頼らざるを得ないからである。特に、阪神淡路大震災等の広域災害が発生した場合、商用系統が停電すると広い範囲にわたって通信機能が麻痺してしまう恐れがある。本研究課題では、この様な状況に対処し得る光通信機器用バックアップ電源システムの開発を目指している。特に、実用化に向けて、太陽光発電電力を最大限に利用するとともに蓄電池容量を最小化し、所望の動作条件下でシステムを極力コンパクト・経済的なものにすることに重点を置いた。 本研究では、まず、系統連系型と独立型の中間に位置し動作が非常に複雑である準自立型の開発システムに対し、システム内の各種パラメータの最適化作業の効率化と高精度化を目指し、太陽光発電システムの動作予測のための高精度計算機シミュレータの開発をおこなった。開発したシミュレータは、従来の太陽光発電システム解析法と異なり,あらゆる気象条件下でのシステム動作予測を高速計算機を用いて数分刻みの短い時間間隔で高精度におこなうことを可能とし,システム全体を視野に入れた各種パラメータの最適化設計を効果的におこなうことが可能となった。このシミュレータ開発の過程においては、パルス放電を用いた蓄電池残存容量の推定法や周波数応答特性に基づく蓄電池のモデル化手法等の蓄電池に関わる新たな特性解析手法の開発もおこなっている。次に、蓄電池充電状態を精度よく検出しシステム内の電力フローを論理回路を介して制御することで,絶えず災害発生後の所定期間の電力供給が保証できる様に蓄電池充電量を確保しながら,平時には日射量の利用率を最大に保ち,かつ商用系からの補充を最小限に抑えた経済的なインテリジェントシステムを実現可能とするマイコン内蔵型電力フロー制御電子回路の開発に取り組み、システム内の新たな電力フロー制御アルゴリズムを開発すると同時に、シミュレーションおよび実験の両面から、その妥当性と有効性を明らかにした。 以上の成果は、従来の太陽光発電システムの設計方法とは異なる新たな有効なアプローチを提案したものであり,今後、より大規模な太陽光発電システムの設計に対しても、十分に適用・展開が可能なものと考えられる。

  • 遺伝的アルゴリズムを組み入れた有限要素・境界要素併用法によるMRI用磁気シールドの三次元最適設計

    1996年  

     概要を見る

     一般に、モデルの重量を軽減する方法として、寸法最適化や形状最適化よりも位相最適化の方が効果的であることが指摘されてきたが、モデル構造のトポロジーを変える位相最適設計は非常に難しく、電気機器の位相最適化に関して論じた研究はまだ少ない。本研究では軽量で高い遮蔽効果を有するMRI用磁気シールドの設計を目指し、シールドの表面形状の変化と内部に穴をあけるという二つの作業に基づく三次元磁気シールドの位相最適化に取り組んだ。具体的には二種類の方法を提案し、一つは上記二つの作業を同時におこなう方法(並列法)であり、もう一つは個別におこなう方法(直列法)である。 そして、この二つの方法を用いて電気学会磁気シールドモデルの三次元位相最適化をおこない、その妥当性と有効性を確認した。 本研究で開発・提案した手法の特長および得られた知見の主なものをまとめると以下のようになる。 (1)提案手法では、磁気シールド問題に対する位相最適化作業の特性を考慮して、磁気スカラポテンシャルを変数とする有限要素・境界要素併用法を磁界解析手法に採用すると同時に、穴の有無のような離散的な設計変数にも対応が容易である遺伝的アルゴリズムを探査アルゴリズムとして組み入れている。 (2)並列および直列の二つの方法を用いて電気学会磁気シールドモデルの三次元位相最適化をおこなった結果、単純な平板形状の場合と比較して、遮蔽効果を保ったまま二割弱の重量軽減が達成された。 (3)並列法は最良の結果を与えるが、直列法も最適化の結果は良好で、計算時間を大幅に短縮できることを考えあわせれば大変有効なものと考えられる。 (4)また、直列法の最適化の工程における作業に対して数値計算結果とあわせて物理的な意味付けをおこない、シールド表面形状だけでなくシールド内部の穴も考慮して形状最適化から位相最適化へ展開することの有効性を明らかにした。

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海外研究活動

  • 電気機器設計への応用へ向けた高速高精度電磁界数値解析技術に関する研究

    2014年09月
    -
    2015年03月

    イギリス   サウサンプトン大学

 

現在担当している科目

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担当経験のある科目(授業)

  • 電気機器

    早稲田大学  

  • 数値解析

    早稲田大学  

  • 電磁気学

    早稲田大学  

 

委員歴

  • 2012年11月
    -
    継続中

    経済産業省 産業構造審議会 保安分科会  電力安全小委員会 委員

  • 2011年10月
    -
    継続中

    一般社団法人日本太陽エネルギー 学会  理事

  • 2014年09月
    -
    2015年02月

    内閣府  大規模地震時の電気火災の発生抑制に関する検討会 委員

  • 2006年10月
     
     

    内閣府 総合科学技術会議 評価専門調査会  「太陽エネルギーシステムフィー ルドテスト事業」評価検討会 委員