Development of traction circuit for converting AC EMU into battery-powered dual source EMU

The authors have developed a battery-powered dual source EMU (test train) for the purpose of interoperable running from an AC electrified line to a non-electrified line. As the EMU was converted from an existing AC EMU, the rating of the developed battery system (1382V-83 kWh) was restricted by the underfloor vacant space. In this paper, we report on the following features and issues of the developed traction circuit: 1) the battery system is directly connected to the DC link of the existing traction circuit without additional power converters, and 2) a low DC link voltage may result in reactive and harmonic components of the collected current. From the results of running tests conducted in JR-Kyushu railway, it is clear that the operational performance of the developed traction circuit and the battery system is sufficient for interoperable service of the EMU. © 2015 The Institute of Electrical Engineers of Japan.