Energy Storage System for Effective Use of Regenerative Energy in Electrified Railways

Motomi Shimada Ryoichi Oishi Daijiro Araki Yasushi Nakamura OVERVIEW: Hitachi is working on the development of energy-saving systems for rolling stock that use lithium-ion batteries to help reduce the environmental impact of railway systems. Two issues associated with regenerative braking are regenerative braking under light load conditions and limits on performance due to motor characteristics, and in response Hitachi has developed respectively an absorption of regenerative electric power function and a regenerative brake with effective speed extended function, proposed an efficient regeneration management system for determining when to operate these functions, and is currently commercializing these technologies. For the function to absorb regenerative electric power, Hitachi has developed the wayside B-CHOP system and on-board sequential regenerative brake system to provide systems that are appropriate to the line and other operating conditions where the system is to be installed. Hitachi will continue to enhance the functions of its energy-efficient systems to meet diverse customer needs.