A self-tuning variable frequency control for multi-level contactless Electric Vehicle charger

This paper proposes a self-tuning controller for a multi-level inductive Electric Vehicle (EV) battery charger application. By controlling the energy injection frequency of the Inductive Power Transfer (IPT) system, multiple charging levels (4 in number) are achieved. Maximum performance is leveraged by the proposed IPT system using its capability of self-tuning the switching operations to the natural resonant frequency of the IPT system, thereby benefiting from soft-switching operations (zero-current switching).Either a digital or analog control circuit can be used to implement the proposed controller. The results are shown by simulating the proposed controller with different charging levels using MATLAB/Simulink. These results show that the proposed controller effectively enables IPT-based contactless EV charging at multiple charging levels, with soft-switching operations. This self-tuning capability is specifically useful in IPT systems that have variable resonance frequency.