Hiroyasu Kobayashi

A study on a method to design energy capacity of wayside energy storage devices in DC-electrified railway systems

In this paper, a method to design energy capacity of wayside energy storage devices (ESDs) is proposed, considering the energy-saving effect and the cost performance of ESDs. Then, the designing method is verified by the numerical simulations. It is also revealed that the train operating diagram does not affect the proposed method to design energy capacity of ESDs.

A control method for on board battery power to compensate the fluctuation of line voltage in case of long distance power feeding in DC electric railway

In this paper, a control method for on board battery power to compensate the fluctuation of line voltage in case of long distance power feeding and to manage the energy of battery in DC electric railway is proposed. Then, the control method is verified by numerical simulations. And, we confirm that the control method can compensate the fluctuation of line voltage and manage the energy of battery. In addition, a practical example of the proposed control method, a method of setting control parameters when setting the minimum line voltage is shown.

Damping control method of regenerative brake control under light load condition utilizing over voltage resistor

Higher DC-link voltage of the regenerating train under light-load regenerative brake control increases the regenerative brake power. However, if the regenerating load changes suddenly, the delay in the motor current control causes the filter capacitor (FC) voltage of the traction inverter increases and may activate the over voltage protection. This paper proposes a damping control method to reduce the peak of FC voltage using the over voltage resistor (OVRe). The proposed method is verified by numerical simulation assuming an actual railway vehicle under the condition of load shutdown at the highest power region, as the worst case conditions. By means of this method, the OVRe can be effectively utilized to reduce the FC voltage spike that results in more saving the substation energy.