Improvement of Utilizing Renewable Energy by Applying Stationary Energy Storage Systems in DC Traction Power Supply System

The installation of PV is spreading toward the realization of carbon neutrality in 2050. The power generation characteristic of PVs is significantly dependent on daylight, season and weather, and is different from those of conventional power sources. In contrast, daily power demand curve of railways is significantly different from the characteristic of PV power. Therefore, the significance of utilizing stationary energy storage systems for the demand control of PVs becomes larger. Firstly, the authors have proposed new charge/discharge characteristics of stationary energy storage systems for charging PV energy from power grid. Secondly, the authors have proposed integrated control of some stationary energy storage systems in the DC traction power supply system. The authors have carried out a study on effectiveness of the demand response (DR) control system for the energy storage systems. This DR control system charges or discharges to stationary energy storage systems in accordance with the power demand. The effectiveness of the proposed control system is confirmed by a train operation power simulator.