A Front-end Coupling Coefficient Estimation Method for the S-LCC Compensated Wireless Power Transfer Systems

This paper proposes a fast and accurate front-end monitoring method to estimate the coupling coefficient in the series (S)-LCC compensated wireless power transfer (WPT) systems. The proposed method can be implemented with only one sensor for the phase information detection of the transmitter current, without requiring any information on the receiver side. A fast frequency-sweeping process is used to obtain the zero-phase-angle frequencies of the WPT systems with the load disconnected. Detailed control algorithm is provided. Experimental results are included to verify that the proposed method can estimate the coupling coefficients within 6 ms while maintaining high accuracies. The largest estimation error is only 1.47%.