Analysis and optimization for Coil Misalignment in wireless power transfer

Performance degradation induced by the misalignment between the transmission and receiving coils is one of issues in wireless power transfer technique. In this paper, a misalignment sensing circuit that can be implemented on the transmitter side is proposed to mitigate the negative effect. The proposed circuit can detect coil misalignment and adaptively tune the duty cycle of pulse width modulation signal of voltage source inverter to compensate the reduction in the power received by the load. Experiment results show that the proposed technology can provide stable output voltage and power when the lateral misalignment is changed from 0 to 5cm and the angular misalignment is changed from 0 to 80°, indicating the potential of the tuning method in the robust WPT applications.