Application of energy storage system for railway transportation in Japan

The electrical energy is easily controllable compared with other energy. In addition, the electrical energy has an advantageous feature for environment. The electrical energy is also used as the driving energy of the rolling stock in railway. On the other hand, to supply the electric energy with stability, the power supply system needs to have a sufficient supply capacity for demand. The feature of the electric power used in electric railways is that the peak power is large and the average power is low. This is a factor of the power cost increase. Moreover, electric railway is increasing effective use for the resurrection energy of the vehicle and the necessity of the voltage descent measures. In addition, an electric railway needs effective use of regenerating energy from rolling stock for energy conservation, and the measure against a voltage drop. To apply the energy storage system to electric railways is one method to solve these problems. This paper describes the example of application and future view of the energy storage system for DC-electric railway in Japan.