Recently, railway companies are introducing energy-saving technologies, such as energy storage systems, energy-saving vehicles, and energy-saving driving operations. This results in the need for a method to accurately estimate the energy-saving effect of each technology. To this end, we developed a method to estimate of train operation energy consumption using the Train Operation Power Simulator. First, we developed a physical calculation algorithm of the Train Operation Power Simulator, unitizing the simultaneous measurements of substations and rolling stocks within a limited feeding section. Then, we developed an estimation method of commercial train operation energy consumption, unitizing the measurements of substations and commercial running data obtain from a train data collection device. We conclude that speed profile, running resistance, and auxiliary power of rolling stock are important for the energy consumption estimation. This study employs an algorithm of the speed profile generator for energy consumption estimation and a randomized braking method that adopts braking patterns derived from actual driving patterns obtained from commercial running data. In addition, this study employs the characteristics of running resistance obtained from running tests and the commercial running data, and the characteristics of auxiliary power obtained from commercial running data.

Short cruise range is one of the major limitations of electric vehicles. To address this problem, dynamic wireless power transfer has been proposed. However, the eddy current loss in foreign matter is one of the greatest disadvantages of dynamic wireless power transfer. Eddy current loss decreases efficiency of wireless power transfer and increases temperature of the foreign matter, which causes burning of of the combustible materials around the foreign matter in the worst case. Herein we propose a wireless power transfer system named in-wheel coil wherein the magnetic flus in concentrated in the tires and wheels. In addition, we propose suitable materials for the tires and the wheels of the system, to reduce the eddy current loss, are proposed using actual measurement data.

Localized wear of pantograph contact strips is a significant problem affecting the current-collecting systems in electric railways, because it may cause fusion of the pantograph head, resulting in devastating damage to the overhead contact wire. However, the causes of localized wear of carbon-based contact strips have not been clarified, and thus, effective prevention measures cannot been established. The purpose of this study is to clarify the generation mechanism of localized wear in copper-impregnated carbon-based contact strips. In this study, the actual locally worn strips were analyzed with a micro Raman spectrometer. The sliding wear behavior of contact strips with different degrees of graphitization of the carbon substrate was investigated using a block-on-ring-type wear tester.

This study proposes and analyzes low-radiation-noise wireless power transfer (WPT) systems with active shielding. Current flows on the additional windings (canceling windings) around the WPT coils with power supplies are used to cancel the magnetic field generated by the WPT coils. The RMS values of the current flowing in the canceling windings are compensated by the active shielding from the utilization of the short-circuited canceling windings to achieve a zero magnetic field. As a result, a 1-kW transmission power and radiation noise reduction of 39.5dB is achieved with the proposed active shielding. The error between the estimated and measured current RMS is 6.2% at the lowest magnetic field. In addition, it is found that the transmission power with the proposed WPT system cancellation method is increased by the magnetic field reduction.

Series hybrid vehicles use power generation systems with engine-powered generators and rectifiers. Systems with permanent magnet synchronous machines and full-wave rectifiers are expected to be efficient and inexpensive. However, it is difficult to increase the output power density of the generator because the generated voltage cannot be increased beyond the induced voltage by permanent magnets. This paper describes the process of improving the power density of a system by adding capacitors to the system to form a resonant circuit.

We have been studying the application of amorphous metals, which have a significantly lower loss than electrical steel sheets, to motors. Thus far, we have studied simple-shaped iron cores that can be machined only by shearing for radial motors. However, it is considered that the loss can be further reduced if the iron core is entirely made of amorphous metal. Here in this report, we report the results of a trial evaluation of a motor in which an amorphous metal is punched using a press die to form a stator core.

In this study, we investigated the effect of the relative position of two stators, with relative angle α, on the machine parameters of flux-modulating hybrid field motors (FHMs). The FHMs are a new type of axial gap motors in which one rotor incorporating iron pieces is sandwiched between two stators, the armature, and the field poles. To consider the magnetic saturation and d-q axis cross-coupling, the machine parameters were calculated using a self-inductance model with current dependencies. From the results of this investigation, we observed the following: 1) Thed-axis flux linkage due to the field poles was the highest when the value of α was maximized. 2) The α has an insignificant effect on the d- and q-axis self-inductances. These findings are useful for future designs of FHMs and their control systems.