Arbitrary power distribution and efficiency optimization for dual-receiver inductive power transfer system with variable coupling

In dynamic wireless charging application for electric vehicles, multi-receiver inductive power transfer (IPT) systems hold enormous potential. However, the couplings and the charging rates are significantly different between vehicles and varies randomly, which causes the systems’ efficiency deviate from their optimal state. This paper presents an analytical model for solving the optimal control variables, which considers arbitrary loads and couplings. Based on the proposed model, with further considering coupling and load restriction, the feasible regulation trajectories of primary inverter and secondary active rectifier phases are derived. Besides, a maximum efficiency point tracking (MEPT) control strategy are designed for achieving selective power distribution and constant current output characteristics simultaneously. Finally, an IPT experiment with dual loads is designed and carried out. The experimental results show that the ideal power distribution can be maintained for each receiver under load voltage, demand current and coupling variations, furthermore, the efficiency of the proposed system can be improved by 3% to a maximum of 89.13% compared to the system without MEPT