Lithium-ion battery installation in traction power supply system for regenerative energy utilization: Initial report of effect evaluation after half a year operation

Previously, some energy storage systems were installed to compensate for voltage drop and to avoid regenerative brake cancelation in d.c. 750V and 1.5kV traction power supply system in Japan. The fly wheel and Lithium-ion (Li-ion) battery, nickel metal hydride (Ni-MH) battery and electric double layer capacitor (EDLC) were used as a storage device. In East Japan Railway Company, Li-ion battery system was installed at HAIJIMA Substation (SS) on Ome Line and started operation on February 20^th, 2013. It is the first application of the energy storage system mainly not for voltage drop compensation but for regenerative energy utilization. In this paper, the effect of Li-ion battery system installed at HAIJIMA SS is evaluated based on the measured data during the practical operation and it is shown that it contributes to more than 5% reduction of total traction power supply at HAIJIMA Substation. The future plan of energy storage application is also mentioned.