Procedures for Identifying Mutual Inductance of Three-Coil Structure for Wireless Power Transfer in Electric Vehicles

Mutual inductance identification of the wireless power transfer (WPT) system is of great significance for improving the system performance. In this paper, a novel mutual inductance identification method for WPT in electric vehicles with three-coil structure is proposed based on the information measured from the primary and relay coils. The method deduces the influence of misalignment on mutual inductance of three-coil WPT system in electric vehicle application scenarios from a new perspective. The results show that the mutual inductance between primary and secondary coils, and the mutual inductance between relay and secondary coils can be estimated at one time by way of index according to the relationship between their ratio and themselves. Experimental results show the correctness of the proposed mutual inductance identification method.