Energy-saving Technology for Railway Traction Systems Using Onboard Storage Batteries

Motomi Shimada Yoshihiro Miyaji Takashi Kaneko Keita Suzuki OVERVIEW: The first application for onboard storage batteries came with the commercialization of series hybrid drive systems that reduced the fuel consumption of diesel trains. Storage battery control has also been used for the absorption of regenerative electric power and to implement the regenerative brake with extended effective speed. Further progress has since led to the development of an efficient regeneration system for making effective use of electric power. Now, Hitachi has conducted operational trials of the regenerative brake with extended effective speed using storage batteries to boost the DC voltage at the inverter input, achieving an increase in regenerative electric power of up to 12.5% (for a 300-V boost). In the future, Hitachi intends to encourage the wider use of onboard storage batteries by achieving a good balance of return on investment, and by working on new energy-saving technologies that are closely aligned with customer needs.