Effective application of superconducting magnetic energy storage (SMES) to load leveling for high speed transportation system

The consecutive pulse power demand of the high speed transportation systems like Shinkansen, gives deteriorative influences to the power supply system and increases its operational costs. To cope with this problem, it has been studied to install the superconducting magnetic energy storage system (SMES) in railway substations. However, the scale of installation becomes too large because of low space factor of SMES, and hampers its realization. Then, it is considered to use SMES only for suppression of the high frequency component of load fluctuation, and to combine with a large capacity battery storage (BEMS), which can not follow fast fluctuation and covers its low frequency component. A novel control scheme of this combined energy storage system is proposed. The fluctuation of power demand caused by high speed train operations in a railway substation is measured separately in the frequency range and used to regulate both SMES and BEMS to suppress fluctuation. With simulation studies based on the load model of high speed train operation at a certain substation, this hybrid approach and its control scheme are verified effective. The system configuration is compact enough to be installed at a substation.