A voltage basis power flow control for charging and discharging wayside energy storage devices in the DC-electrified railway system

Wayside energy storage systems (ESSs) in DC-electrified railway are recently studied as one of methods to save regenerative brake energy. Voltage basis control method to regulate the filter capacitor (FC) voltage in order to increase the assisting and absorbing power was developed. The voltage controller gain in this method should be set high for more energy-saving effect. However, it causes sometimes an oscillation of FC voltage. A method to design controller gain considering the trade-off between energy-saving effect and anti-oscillation of FC voltage is proposed in this paper.