100kW Electric Bus Wireless Charging System with Calculating Method for Hybrid Energy Storage Capacity

For the application background of electric buses being wirelessly charged at the stopping locations on bus route, a 100 kW electric bus wireless charging system with supercapacitor (SC)-battery hybrid energy storage is designed. In addition, a calculating method for hybrid energy storage capacity is proposed to select the appropriate capacities of system hybrid energy storage devices and thus reduce the weight of bus. Firstly, the equivalent circuit model of the wireless power transfer (WPT) system with SC and battery being loads is analyzed. Then, for the dynamic change of SC equivalent resistance, the SC detection, the wireless data communication, and the power regulation are adopted in the system. Finally, the 100 kW wireless charging system designed in this paper is implemented and verified by experiments. When the transfer distance is 0.45 m, the output power can be 80.2 kW with 89.6% transfer efficiency. Moreover, according to the experimental results and the bus energy consumption survey, the energy storage capacity is calculated by the proposed calculating method.