An Anti-Misalignment Method for Inductive Power Transmission System Based on Working Mode Switching

In Inductive Power Transfer (IPT) systems, coils misalignment can significantly alter the system’s output power, thereby compromising operational stability. To address this issue, this article proposes a mode switching approach. Firstly, let the IPT system operate under conditions of primary-side inductive detuning and secondary-side resonance. Subsequently, by modifying the inverter’s switching frequency and conduction scheme, it is possible to vary the system’s operating frequency and the degree of primary-side detuning, thereby producing two distinct output power curves. Therefore, the controller can dynamically change the switching frequency of the inverter and the degree of primary-side detuning based on coil misalignment, thereby mitigating the effects of variations in the coupling coefficient on the output power by switching the output power curve. Finally, the parameter selection step and open-loop control system are presented. An experimental prototype with an output power of 600 W was constructed to validate theoretical analysis. The experimental results indicate that, when the system load is set to 10.4 Ω and the coupling coefficient varies between 0.23 and 0.50, the output power fluctuation of the system is 4.5%, and the transmission efficiency is 91.7%. The experimental results demonstrate that the proposed working mode switching method significantly improves the system’s anti-misalignment characteristics.