... the Emerging Era of Smart Grids Energy Storage in the Emerging Era of Smart Grids 24 conventional cell/module voltage equalizers are presented and technical concerns regarding their circuit ... Propulsion Conference, ISBN 978-1- 42 44- 1 848 -0, Harbin, China, September 3-5, 2008 Energy Storage in the Emerging Era of Smart Grids 40 Yoshida, H., Imamura, N., Inoue, T., Takeda, K. and Naito, ... systems, the rotor is accelerated by the electrical machine operating in motor mode. When required the energy stored in the rotor can be released by operating the electrical machine in generator...