Load Detection Method and Control of Class-E Inverter for Dynamic Wireless Power Transfer

Due to the electrical isolation between the transmitter side and the receiver side in dynamic wireless power transfer (WPT), load detection becomes an essential function for saving energy and safety issues. This paper proposes a reliable load detection method without any auxiliary switch and communication device. The proposed method, which is based on the energy equilibrium equations, only needs to sample the input DC current, avoiding sampling the high frequency signals in the resonant tank. This paper firstly determines the threshold current for detecting load by analyzing the power dissipation in the Class-E inverter. Then the details of the control procedure and the design of parameters are also discussed. Finally, experiments of the dynamic WPT system with Class-E inverter are implemented to verify the availability of the load detection method and the control method.