A hybrid energy storage with a SMES and secondary battery

An energy storage device with high energy density and high power density is desired for compensation of fluctuating loads such as railway substations and distributed generations such as wind turbines. Typically, a SMES (Superconducting Magnetic Energy Storage) has higher power density than other devices of the same purpose, and secondary batteries have higher energy density than SMES. In this study, the authors propose a hybrid energy storage system composed of a superconducting magnet and secondary battery for an energy storage system with high energy density and high power density. The sharing method of power for each storage device using a Fuzzy control and filters, simulation for the compensation of railway loads and the power of wind turbines are presented.