Overview of Coil Designs for Wireless Charging of Electric Vehicle

With the electric vehicle (EV) market growing fast, the emerging wireless EV charging technology has attracted more and more attention in recent years. As a key part of wireless charging system for EVs, the coil design is indispensable for improving the system performance. This paper presents an overview of coil designs for wireless charging of EVs, which addresses their basic structures, operating principles, and distinct features. The basic topologies including the circular rectangular pad (CRP), circular pad (CP), homogeneous pad (HP), double-D pad (DDP), double-D quadrature pad (DDQP), and bipolar pad (BP), are introduced and discussed. Also, the corresponding advantages and limitations of each topology are analyzed and discussed. Besides, some key issues of practical design problems are compared in the coil topologies. Finally, the human exposure issues are revealed.