A Novel Approach for Mutual Inductance Estimation in Wireless Power Transfer

In this work, a mutual inductance estimation (MIE) method for multiple transmitters (multi-Txs) wireless charging systems is proposed. The method involves intermittently interrupting the power to the transmitter, while simultaneously collecting current data, to estimate the mutual inductance parameters. The estimation process does not involve high-order calculations, making it simple to compute. The proposed method eliminates the need for continuous high-speed real-time feedback signals from the receiver (Rx) to adjust current or voltage. Hence, it avoids the interference issues of high-order switching harmonics between power converters and the wireless communication link. This enhances the reliability and reduces the cost of the wireless communication module. The simulation results prove that the proposed method can accurately estimate mutual inductance under various coupling conditions, with errors consistently below 3.5%.