A Self-Tuning Method for Performance Enhancement of Wireless Power Transfer under Capacitance Drift

The performance of wireless power transfer (WPT) system is dependent on resonance between coil inductor and compensation capacitor. However, temperature variation or aging would lead to capacitance drift of the compensation capacitor. This factor causes detuning of the WPT system which affects power transfer performance. In order to solve the problem, a self-tuning method for anti-capacitance drift is proposed in this work. Firstly, the influence of capacitance drift on power transfer is analyzed. Then, a novel WPT system is designed by introducing a nonlinear magnetic ring. The characteristic of the magnetic ring is presented and the proposed WPT system is mathematically described. Finally, simulation work is carried out to verify the effectiveness of the proposed method.