Our research group designed two electric buses, a small-sized bus for driving on ordinary roads, and a medium-sized bus for driving on expressways. Analyzing the data obtained from verification test, we found a characteristic phenomenon related to regenerative energy on the expressway. In this paper, analysis of evaluation related to this phenomenon by simulating three different driving routes with the medium-sized electric bus is summarized.

In this paper, a series-type plug-in hybrid vehicle simulator is used to validate the distance traveled dependence of environmental performance of the plug-in hybrid vehicles proposed in our previous paper is established. First, the characteristics of the distance traveled dependence such as cross-point and the difference of CO2 emissions between AE and BLD controls are confirmed. Also, the appropriateness and usefulness of the propositions, including the CD mode control selection policy, the optimal BLD control, and the indicator BCPI (blended control performance indicator), which can simply evaluate the effect of BLD control, are valid.

Wireless charging technology for heavy-duty vehicles has been investigated for eco-friendly transportation. We present a new wireless power transfer system for 44 kW rapid charging of electric buses. Transmission distance between charging pads is from 10 to 13 cm. The large air gap can be fulfilled by the ordinary kneeling function equipped on most low-floor buses. Dual-block parallel transmission with opposite-phase-current-feeding suppresses magnetic radiation. The system operates in the common 85 kHz band with the light-duty vehicle system. The results of its field test and public road operation of two electric buses to confirm the effects of CO2 eduction and energy saving are described.

Our research group designed and made two trial production for two electric buses, a small-sized bus for driving on ordinary roads and a medium-sized bus for driving on expressways. Approximately one-year verification test was conducted in the Metropolitan Expressway Bay Shore route and surrounding areas in Japan. In this paper, analyzed results focused on the regenerative energy while traveling on expressways compared to ordinary roads made by heavy-duty electric vehicles will be summarized.

To reduce CO2 emissions of a conventional diesel engine garbage truck, we developed an electric motor driven fuel cell garbage truck. It was designed based on analytical result of two garbage collection routes, Kanmon-route and Imajuku-minami route of Shunan City of Yamaguchi Prefecture, Japan. It was trial produced to satisfy the same driving performance as a conventional diesel engine garbage truck. A chassis dynamo test was performed to compare the vehicle component energy consumption with a conventional diesel engine garbage truck during two driving scenarios, general driving (Tokyo No. 8 mode) and garbage collection driving (Tokyo garbage collection mode). From the chassis dynamo test, the energy consumption reduction rates when the diesel vehicle was replaced by the fuel cell vehicle were 69% in the Tokyo No. 8 mode and 81% in the Tokyo garbage collection mode. The CO2 emissions reduction effect was calculated using correction to the energy consumption of the general route in Shunan City based on the chassis dynamo test results. In case of using energy consumption correction based on the total travel distance and the weight of garbage, we estimated that the improvement of the fuel efficiency was between 1.6 to 1.8 times in terms of CO2 emissions. For further improvement to reduce energy consumption of a fuel cell garbage truck, three measures (vehicle weight, PTO gear ratio and regeneration energy) were considered by the vehicle simulation.

Plug-in hybrid vehicles (PHVs) have two driving modes, which are known as charge-depleting (CD) mode and charge-sustaining (CS) mode. The environmental performance of a PHV differs greatly based on the travel distance when the PHV switches from the CD mode to the CS mode. This paper focuses on the low-carbon effect and energy cost reduction effect of PHVs and numerically describes the dependence of the effects on the distance traveled. It also accounts new knowledge obtained through a detailed analysis and examination of the mathematical equations.

To reduce CO2 emissions of garbage truck, we developed a fuel cell garbage truck. It was designed based on analytical result of the garbage collection route, Shunan city of Yamaguchi prefecture, Japan. We performed bench test of hybrid power plant system, which is consisted of fuel cell system and Li-ion battery pack. We developed vehicle simulation model and analyzed hydrogen consumption and component loss in different power distribution methods.

An electric motor driven fuel cell garbage truck was developed to reduce CO2 emissions of a conventional diesel engine garbage truck. A fuel cell power plant bench test was performed to confirm the fuel cell power plant performance and to develop a simulation model. Based on the simulation model result, hydrogen consumption and each component losses were compared by two different fuel cell system types and output control methods for weight reduction during one day driving in the Shunan City, Yamaguchi Prefecture. The recent mass production of fuel cell system and battery pack were considered for the weight reduction.

The two opposite concepts of BE bus (battery-electric bus) which were 'Short-range Frequent-charging-type' and 'Night-charging-type' low-floor buses, were designed and evaluated. Firstly, the current technical level of battery and charging equipment had taken into account to conduct the vehicle design of both BE buses. In additional, the ideal performances of battery and charging equipment for fully substituting the highly used diesel buses in the very densely packed city transportation routes would be clarified in the paper.

A long-term operation test in cold region of electric buses on public roads was performed in Nagano prefecture as a project of the Japan Ministry of the Environment from 2011 to 2014. For this project, the short-range frequent-charging type electric buses, 'Waseda Electric Buses (WEBs)' were developed. WEB-3, one of the test vehicles, was driven for 42,114 km over 902 days and charged 4,298 times. In this paper, the following was obtained. (1) The battery performance deterioration is measured and proofed to be predictable. (2) One strategy is advised for expanding battery lifetime. (3) Even started the operation at sub-zero environment, the performance of vehicle was not affected.

A long-term operation test of electric buses on public roads was performed in Nagano as part of a project of the Japan Ministry of the Environment from 2011 to 2014. For this project the short-range frequent- charging type electric buses, «Waseda Electric Buses (WEBs)» were developed. WEB-3, one of the test vehicles, was driven for 41,724 km without any major problems and had advantages to reduce 28-42% of CO2 emissions and 57-64% of energy costs, compared to conventional diesel buses. The battery performance deterioration is also confirmed to be predictable, therefore two suitable strategies is advised for expanding battery lifetime.

Various studies were conducted from the aspects of both the battery cells and the module with the aim of making more effective use of the battery capacity. As a result, after 77 cycles of driving and rapid charging, the capacity degradation of the battery module as a whole was 7.7 % and it was determined that the cause of this additional 0.7 % degradation of the capacity was the loss of cell balance. In addition, by adopting module balance coefficient (945
) that was proposed as an indicator to show the available percentage of the lowest capacity cell in the module, new cell balancing rules were created that do not significantly affect the convenience of vehicle operation.

Degradation mechanisms of lithium iron phosphate battery have been analyzed with calendar tests and cycle tests. To quantify capacity loss with the life prediction equation, it is seen from the aspect of separating the total capacity loss into calendar capacity and real cycle capacity loss. The real cycle capacity loss of total capacity loss was derived by subtracting the calendar capacity loss parts during cycle tests. It is considered that calendar capacity loss is dominated by SEI formation. On the other hand, real cycle capacity loss includes structure disorder of electrodes and promotion of SEI growth such as delamination and regrowth. Generally, the test results indicated that capacity loss increases under high temperature and SOC condition, and SOC range (ΔSOC) is not related to the loss. However, we founded that the test results under 5°C condition do not exactly show the same tendency of degradation. As a result, the life prediction equation is based on the chemical kinetics and it can only be adopted only beyond the 15°C temperature limitation. At this time in life prediction equation, to take ΔSOC into consideration and describe the real cycle capacity loss specifically with amounts of lithium-ion intercalation/deintercalation, the processing amount of current is adopted as the standard of capacity degradation instead of the cycle number. Finally, it is considered to be possible that certain reactions such as further structure disorder or lithium plating caused under low temperature. However, we also founded that DC internal resistance tests results indicated that only calendar capacity loss can apply to chemical kinetics. It is necessary to consider the other construction method of the life prediction equation in the future.

Electric buses have superior environmental performance because they emit no CO2 and other exhaust gases while driving. However, in terms of more popularization of electric buses, it is essential to improve battery performance and realize user-friendliness of charging. To resolve these issues, a concept "short range running and frequent charging" was formulated. Under this approach, the authors have studied methods of greatly reducing the amount of large, heavy, and expensive battery. Research on non-contact inductive power supply (IPS) system has also been conducted as a way of improving charging convenience. A long-term operation test of electric buses was performed in Nagano prefecture as part of a project organized by the Japan Ministry of the Environment from 2011 to 2014. For this project the short-range frequent-charging type electric buses, "Waseda Electric Buses (WEBs)" were developed and tested on public roads to make clear the environmental performance and energy costs. WEB-3, one of the test vehicles, was driven for 41,724 km without any major problems and had advantages to reduce 28 - 42 % of CO2 emissions and 57 - 64 % of energy costs, compared to conventional diesel buses. And it was estimated on Matlab simulation model that total energy consumption could be reduced by 11 % with vehicle weight reduction, modifications of drivetrain and other components.

Electric buses have superior environmental performance because they emit no CO2 and other exhaust gases while driving. However, in terms of more popularization of electric buses, it is essential to improve battery performance and realize user-friendliness of charging. To resolve these issues, a concept "short range running and frequent charging" was formulated. Under this approach, the authors have studied methods of greatly reducing the amount of large, heavy, and expensive battery. Research on non-contact inductive power supply (IPS) system has also been conducted as a way of improving charging convenience. A longterm operation test of electric buses was performed in Nagano prefecture as part of a project organized by the Japan Ministry of the Environment from 2011 to 2014. For this project the short-range frequentcharging type electric buses, "Waseda Electric Buses (WEBs)" were developed and tested on public roads to make clear the environmental performance and energy costs. WEB-3, one of the test vehicles, was driven for 41,724 km without any major problems and had advantages to reduce 28 - 42 % of CO2 emissions and 57 -64% of energy costs, compared to conventional diesel buses. And it was estimated on Matlab simulation model that total energy consumption could be reduced by 11 % with vehicle weight reduction, modifications of drivetrain and other components.

This paper discusses the effects of different engine control methods on vehicle performance using a compact range extender-type PHV with a series-hybrid system. Vehicle performance was analyzed and compared in detail using two typical engine control methods: the variable control method, which drives the engine in accordance with the vehicle load, and the constant control method, which drives the engine at a constant maximum load efficiency. Specifically, by evaluating the performance in both driving tests by a test vehicle and driving simulations, we identified the characteristics of each engine control method and confirmed which is superior in terms of the seven PHV performance indices determined by the Japanese Ministry of Land Infrastructure and Transport. The comparison results quantitatively verified that the constant control reduced engine loss but caused battery loss to increase. However, since the best control method is determined by the engine and battery loss characteristics of the target vehicle, the constant control method enables superior mileage for the vehicle examined in this research due to its large engine loss reduction effect. In our case, 7.9% improvements of the charge sustaining mode mileage FCS and 7.6% improvements of the combined mileage FPH have been achieved by adopting the constant control method.

This paper addresses the method of detailing the motor system including the inverter and the boost converter of plug-in hybrid vehicles (PHVs). In the past, we had to use the actual measurement data such as efficiency map to calculate the loss of a motor system. However, by estimating the output current of the motor system, allows us to separate the one loss into losses caused by the inverter, the boost converter and the motor. Based on the separation of the losses, we can then build a multi-voltage motor system or estimate the losses of the different ranks of vehicles.

The Waseda Advanced Electric Micro Bus (WEB) has been developed and tested for convenient regional public transportation. By adopting an advanced hybrid electric power supply system (Nickel Sodium Chloride Battery &amp
Super capacitor for WEB-1, Nickel Sodium Chloride Battery &amp
Li-ion Battery for WEB-2) and related key components, significant improvements in energy consumption and CO2 emissions have been achieved, compared to that of an equivalent diesel micro bus. © 2010 WEVA.

Contactless rapid charging inductive power supply (IPS) system has been developed and tested as a charger for small size electric-driven vehicles. By using the developed system, charging can be carried out safely, easily, and in a short period. Optimizing the external circuits of track and pick up of IPS achieved significant improvements in efficiency, power factor during non-contact power transmissions. This paper also reports on the development of Waseda Advanced Electric Vehicle (WEV) equipped with developed IPS system.

This paper reports on the development of the Waseda advanced Electric Vehicle - 0 that is equipped with a non-contact inductive power supply (IPS) system. By using the developed IPS system, charging can be carried out safely, easily, and in a short period. We summarize the vehicle performance evaluation results obtained from related tests.

Our research group has developed a non-contact rapid charging inductive power supply (IPS) system with safe, simple, and rapid recharging characteristics for electric-driven vehicles principally for electric vehicles and plug-in hybrids. Outstanding features of the system include high efficiency, significant weight reduction, and a long air gap, and have been implemented through the optimisation of the shape of the track and pickup. This paper mainly focuses on the results of performance evaluation tests of the developed system. The results obtained are listed below, a) Through non-contact electric power transmission experiments, the attainment of a 92% total efficiency was confirmed during 30 kW transmissions, b) The developed IPS was installed on an electric micro-bus WEB-1 Advanced. Non-contact power transmission was conducted, and the successful recharging of the on-board battery was confirmed, c) The weight of batteries mounted can be reduced by implementing the IPS on electric vehicles with frequent recharging. Under the operating conditions studied in our project, it was concluded that an approximately 9% reduction in electric consumption rate can be achieved through 11% reduction in vehicle weight, d) Taking advantage of the increased flexibility in weight resulting from implementation of the IPS, a narrower SOC operating range can easily be achieved for the purpose of prolonging battery life. Under the operating conditions studied in our project, it was concluded that an approximately 55% reduction in SOC range can be achieved.

The Waseda Advanced Electric Micro Bus (WEB) has been developed and tested for convenient regional public transportation as a part of the Advanced Electric Micro Bus Transportation System Project supported by NEDO. The bus system is characterized by the significantly reduced amount of batteries for lightweight. The batteries are occasionally rechargcd by a non-contact inductivc rapid- charging system (Inductive Power Supply System: IPS System) at the terminal station. By adopting an advanced hybrid eleclric power supply system (Nickel Sodium Chloride Battery &amp
Super capacitor for WEB-1, Nickel Sodium Chloride Battery &amp
Li-ion Battery for WEB-2) and related key components, significant improvements in energy consumption and C02 emission have been achieved, compared to that of an equivalent diesel micro bus. Copyright © (2007) by the Electric Drive Transportation Association.

In order to assess the effect of PEM-FC poisoning resulting from impurities on PEM-FC performance, this paper investigated contents as follows
· Estimation for composition and concentration of impurities contained within hydrogen fuel and air. · The prediction of poisoning extent and proposal of assessment index for impurity poisoning. · Allowable mixing concentration of impurities for the standard H2 fuel. The analysis and experiment are conducted under 70 °C and 1 bar for operating temperature and pressure. PEM-FC with Pt and Pt-Ru type catalytic-electrode was used. It was observed that: · CO poisoning was reversible but H2S and SO2 poisonings were irreversible. It was also confirmed that sulfur compounds poisoning was very strong. On the contrary, poisoning of HCHO and CH4 etc. was slight or negligible. · In case of cathode electrode, the effect of NO2 and SO2 poisoning on PEM-FC performance was severe when CO poisoning was negligible. Copyright © 2007 SAE International.

The driving conditions of suburban transit buses were investigated with a chartered bus. Based on this data, a series hybrid system was designed for transit buses from the viewpoint of the acceleration performance and the energy saving. In order to measure the electric energy flow on board, the dynamometer bench tests and the static simulated experiments were carried out with storage batteries and ultra capacitors. It was clarified that the charge discharge loss in the storage devices can be estimated by the calculation using the internal resistance and current. And, the energy efficiency of the series hybrid system was evaluated in compared with conventional engine-powered buses for a trial.

This paper covers our investigation into a decline in fuel cell (FC) performance resulting from hydrogen fuel containing impurities. This is a serious problem in case of adopting the methanol or gasoline reforming approach as a means of supplying fuel to FCs. The results are summarized as follows:
(1) Components of the gas generated by the reformer adopting the steam reforming and auto thermal reforming approach were predicted and specific components and concentrations were identified;
(2) Various experiments and analyses were conducted to determine the adverse effect of CO, CH4, HCHO and HCOOH poisoning on the performance of FC. (C) 2003 Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved.

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.

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.

In this study, the series hybrid electric system is recommended as suitable power systems of the motor vehicles in urban area. It is important for this system to improve the comprehensive energy efficiency when components are combined, and to evaluate it appropriately. In this report, the technique to grasp energy loss in detail that occurs when electric power flows complicatedly in the series hybrid power system has been examined and the energy efficiency of the series hybrid power system on urban driving has also been evaluated. Copyright © 2001 Society of Automotive Engineers, Inc.

In this paper, we propose a novel block feeding method for use in linear induction motors. The proposed method involves shifting of the excited section at every coil. Using the proposed method, the excited-section length can be shortened greatly compared with that in the ordinary method shifting at every block section. Thus, the power consumption becomes lower, improving efficiency. In addition, by short-circuiting the coils at both ends of the excited section during shifting, continuous power supply becomes possible, and thus electric transient phenomena are reduced. We confirm the validity of the method by finite element analysis and experiments.

This paper treats a novel linear hybrid motor (LHM) by both induction and synchronous operations. The proposed motor consists of one pair of linear synchronous motors (LSMs) and a linear induction motor (LIM). The primary-cores of both LSM and LIM have a common ring winding, and the secondary solid-conductor is arranged in both LIM and the interpole space of LSM, The feature of the motor is that the undesirable vertical force in LSM is offset by the symmetrical double-sided construction and the secondary is capable of self-starting by induction operation. From the investigation by the three-dimensional finite element analysis and experiment, we derive an optimal exciting condition for starting, and then verify that the proposed LHM is effective for practical use.

In this study, we attempt to analyze characteristics of Single-sided Linear Induction Motor with a short primary member and a complicated secondary structure, which consists of solid-plate conductor section and a winding one. For this purpose, electromagnetic field analysis by 3-D FEM is combined with electric circuit analysis and motion equation. Here, electric circuit analysis involves the primary and secondary windings. Focusing on the distributions of secondary induced current and thrust force, we discuss various transient phenomena that develop at the boundary between different secondary structures. Finally, to suppress the aggravation of characteristic caused by the secondary structural transition, we improve the boundary.

This paper treats the optimization of rotor construction in the permanent magnet synchronous motor (PMSM). While the field system of PMSM has generally one magnet per pale, we replace the magnet into. plural sub-magnets. The dimensions of each sub-magnet are determined by the concept of guise width modulation (PWM). By adopting the proposed rotor construction, we can not only reduce the space harmonics of the air-gap field but also provide space for damper winding around the direct-axis. From the investigation by hybrid FE-BE (coupled finite element and boundary element) method combined with bath electric circuit and motion equation, we verify that the proposed construction is effective for practical use in view of both the harmonics reduction and the damping effects.

While the commercial motor produces only one-dimensional (linear or rotary) motion, we propose a new type of tubular linear induction motor (TLIM) with two-dimensional motion in this paper. The proposed motor consists of plural short primary LIMs arranged on the same circumference and a common secondary. By applying independently energized ring-windings of double-layer to the primary, we can achieve both the reduction of coil-end region and the freedom of alternating current supply. The secondary conductor is capable of producing any one of rotary, linear, and helical motions by controlling the phase of supply currents in each primary winding. We first investigate the driving characteristics of the proposed motor by three-dimensional finite element analysis, in order to obtain the optimal feeding conditions to increase the subsidiary rotary-force. Then, we make the experimental machine based on the analysis results. In addition, we deduce an optimal arrangement of the primary slot currents enhancing the secondary thrust in the short primary LIM. Finally, we confirm the adequacy of analytical results by experimental ones.

In this paper, we propose a novel switching method for shortening block feeding portions in short secondary member linear motors. The proposed method involves shifts at every coil, which makes the length of feeding portions much shorter than that in the ordinary method with the shifts at every block section. Resulting advantages for adopting the proposed method are summarized as follows:<br>1) Concerning power supply: Owing to the extremely short feeding portions, improvement of power factor and efficiency becomes possible. And, since power is supplied to each coil for a very short time, the rating becomes a short-time one.<br>2) Concerning electric transient phenomena: By short-circuiting coils at both ends of the feeding portion during shifts, continuous power supply and smooth shifts become possible, reducing electric transient phenomena.<br>The study is carried out through experiments as well as simulations using a hybrid method of the magnetic-fields and the electric-circuits analysis.

There are several difficulties in calculating eddy currents in plates with thin slits by the finite element method (FEM). Under the influence of flat finite elements at slits, the accuracy of analysis decreases and the computation time increases. In this paper, using the A - phi method, we propose a novel technique, which overcomes those defects. The feature of the method is to adopt double nodes for the electric scalar potential phi at slits, but not to the magnetic vector potential A. Adopting this technique, slits are equivalent to current barriers that have infinitesimal width. Some numerical results, which show the validity of the proposed method, are also presented.

The slot harmonics produce a cogging torque and a crawling in a linear induction motor (LIM) with a ladder type rotor. To avoid those defects, we sometimes adopt the V-skewed rotor (or stator) which rise no lateral force. In this paper, we investigate the skew effect by the three-dimensional finite element analysis with A-φ method and specify significant points for adopting skewed slots.<br>Based on the above approach, we evaluate the skew effect in the LIM, comparing it with the experimental data to confirm the validity of the analysis. The follows are confirmed: (1) the improvement of the cogging torque by introducing V-skewed rotor; (2) the decrease in the thrust force and increase in the sucking force as making the skew angle bigger, and the abnormal temperature rising in V-skewed rotor; (3) the decrease of the abnormal temperature rising by optimizing the shape of rotor; (4) the validity of the skewed stator for short stator machines. And we propose a method that put two stators skewed in the opposite direction to each other for the double-sided LIM.