A Method for Determining Substation Output Voltage for Energy Saving Focused on Regenerative Train FC Voltage in DC-Electrified Railway

In DC-electrified railway, when the substation output voltage is high, the train voltage increases, and light-load regenerative brake control is activated, resulting in a decrease in the regenerative energy. When the substation output voltage is low, the main circuit loss and power loss increase owing to the increase in the acceleration time and current. Therefore, the substation output voltage that maximizes the energy-saving effect is determined by the trade-off relationship between regenerative energy and consumed energy. The purpose of this study is to focus on the correlation between the regenerative vehicle FC voltage and regenerative energy reduction and its position dependence, and to propose a method for determining the output voltage of multiple substations that can maximize the regenerative power beyond substations. The proposed method reduces the number of voltage parameters, which contributes to a considerable reduction in the number of simulations.