A Frequency Modulated Maximum Power Point Tracking Method for Wireless Charging Systems

Inductive power transfer (IPT) technology has gradually matured in electric vehicle (EV) charging. However, most of the existing designs have not considered the system inductance variation caused by factory manufacturing tolerance and ambient environment change, which can weaken the power transfer capability of the IPT systems significantly. In this paper, the effects of the inductance variation on the power transfer capability of IPT systems were investigated. A 10% coil tolerance can lead to a power reduction of up to 61.3%. To fill this gap, this paper proposed a frequency modulated maximum power point tracking (MPPT) method to adjust the inverter frequency to achieve its maximum power point. The simulation results under different circumstances were analyzed. The experimental results show the feasibility of this method to improve the power transfer capability.