A dynamic tuning method utilizing inductor paralleled with load for inductive power transfer

The detuning of inductive power transfer (IPT) system which is usually caused by the component tolerance and aging of the inductors and capacitors can decrease the system efficiency. In order to tune the receiver circuit of IPT system, an inductor is paralleled with a diode full-bridge rectifier cascaded with a Buck converter and load serving as a tuning circuit. By changing the duty cycle of the buck converter, the impedance of the tuning circuit can be adjusted which can be used to compensate the reactance caused by detuning. The experimental results in a 400W prototype show that with 15% tolerance of the resonant capacitor in the receiver side, the system efficiency with the proposed method can reach 91% which has an improvement by 7.9% compared to the detuned system.