A Compact Coupler with Integrated Multiple Decoupled Coils for Wireless Power Transfer System and its Anti-Misalignment Control

Wireless power transfer (WPT) is a promising way of charging electric vehicles (EVs) for its convenience, safety, physical and electric isolation. For satisfying the high-power application or rapid charging, WPT systems based on multiple coils are usually used. Nowadays, LCC compensation is a commonly used topology. However, the conflict between the installation space limitation and the large volume induced by compensated inductors and multiple coils brings the critical challenge for EVs charging electric vehicles' charging. In this article, a method of integrating multiple decoupled coils is put forward. All the main coils and compensated inductors are integrated together for compacting the WPT system. Characteristics of the coupler are analyzed when it exists a misalignment both in x- direction and y-direction. Besides, an antimisalignment strategy based on optimizing the phase difference of current in main coils is proposed. Finally, a 3kW laboratory prototype is built to verify the proposed compact coupler and antimisalignment control strategy. The system output power only drops 3.2% and 9.2% respectively with a -200 mm and +200 mm misalignment in the x-direction compared with full alignment by adopting the proposed antimisalignment method. When it is fully aligned, the system can achieve 94%peak efficiency.