Evaluation of installation effect of the energy storage system in D.C. traction power supply system

One of the initiatives toward traction energy saving on the railways is effective utilization of the regenerative energy. Greater efficiency in energy use is achieved through the installation of the energy storage system by discharging the energy depending on the load situation. The energy storage systems are usually used flywheel, nickel-metal hydride batteries, lithium-ion batteries, electric double layer capacitor (EDLC), etc. East Japan Railway Company also installed two energy storage devices using lithium-ion batteries at Haijima and Okegawa substations. This paper describes the installed results of these energy storage systems. Furthermore, the installation effect was estimated using two methods at Okegawa substation.