Wireless EV Charging System without Air-Gap and Misalignment

Large air-gap and misalignment in static wireless charging of electric vehicles (EVs) cause two critical safety issues: human exposure to electromagnetic field and metal object overheating. Moreover, a large air-gap and a misalignment will degrade efficiency performance and complicate the design of a wireless charging system. This paper proposes a static wireless EV charging system with a mechanical structure to ensure zero air-gap and zero misalignment. The mechanical structure is purely passive and does not contain any motors or drives. Based on this structure, a pair of couplers which have a coupling coefficient of 0.94 are designed and analyzed. The performance of the charging system is investigated and compared with an ordinary charging system which has a large air gap.