Abstract
In recent years, the concern over an effective energy saving measures has risen. To reduce the environmental impact of railway, electric energy storage systems have been installed to some substations in East Japan Railway Company (JR-EAST). The research of electric energy storage system mounted Nickel metal hydride battery modules (Ni-MH storage system) was examined for effective utilization of regenerative braking power. This experimental verification test was performed at Kori substation, on Ome-line in JR-EAST. In this paper, as one of the examination results, the charge evaluation of Ni-MH storage system is explained. As for this examination at Kori substation, this storage system was charged about 60-80% directly from rectifier, not from regenerative power (it is called "direct charge"). It became clear that direct charge amounts depend on regenerative current. In this respect, to increase regenerative current, the supply voltage, in other words, DC bus voltage at Kori substation was decreased. Consequently, decreased DC bus voltage made regenerative current double, and it made direct charge from rectifier decreased almost 50% in comparison with usual condition.
