A Dynamic Tuning Method of Wireless Power Transfer System Based on Phase-Controlled Inductor Circuit

Wireless power transfer (WPT) technology has increasing potential as the charging infrastructure in railway transportation and the interaction between large-scale or electric vehicles and power grid. To solve the problem of receiver side detuning caused by changes in coil spacing and equivalent DC load in wireless electric vehicle charging system, an LCC-S WPT system with receiver side dynamic tuning method is designed. This paper first analyzes the transmission characteristics of the LCC-S WPT system and the working principle of the phase-controlled inductor circuit. The phase-controlled inductor circuit is applied to the series compensation capacitor at the receiver side, and the equivalent capacitance value is dynamically adjusted to make the receiver side always resonate. The experimental results demonstrated the effectiveness of the proposed dynamic tuning method, which can restore resonance at the receiver side and improve the output power when the coil spacing and equivalent DC load change.