Coil Interoperability and Misalignment Tolerance of Electric Vehicle Wireless Charging System Based on Multiple Self-Decoupled Transmitting Coils and Vector Synthesis Strategy

In recent years, the rapid development of electric vehicles (EVs) has led to the continuous innovation of the charging technology. EV wireless charging is safer and more convenient than conductive charging, and the researches about this aspect are more in-depth. Three types of planar coils, namely unipolar coil (Q), bipolar coil (DD), and quadrupolar coils (QUA) are usually utilized at the receiving side (Rx) in the EV. According to different design requirements, various types of Rx coils will be installed by the manufacturers of EVs. Modifying the structure of the transmitting coils (Tx) to improve interoperability is the key issue of the wireless charging technology. In this paper, a multi-channel topology with four decoupled Q Tx coils is proposed. The vector synthesis strategy of equivalent transmitting mutual inductance is adopted. Based on the achievement of interoperability for three types of Tx coils, the high misalignment tolerance on the directions of both X/Y axes is also achieved. An experimental prototype is built, and the effectiveness of the topology is verified. The proposed multi-channel topology is compatible with Q, DD and QUA coils, and high misalignment tolerance is achieved.