Application of a hybrid energy storage system in the fast charging station of electric vehicles

Fast charging is a practical way for electric vehicles (EVs) to extend the driving range under current circumstance. The impact of high-power charging load on power grid should be considered. This study proposes an application of a hybrid energy storage system (HESS) in the fast charging station (FCS). Superconducting magnetic energy storage (SMES) and battery energy storage (BES) are included in HESS. Based on the quick response of SMES and the high energy density of BES, power magnitude and power change rate of FCS can be limited by compensation of HESS. A controller is designed to generate real-time power demand to HESS. As a part of the control strategy, the energy regulation control of SMES is highlighted. The regulation control is necessary for SMES to deal with energy imbalance in continuous operation; meanwhile it is beneficial for battery life. Finally, feasibility of this control strategy is verified by simulation.