Contactless Power Transfer System for Electric Vehicle Battery Charger

Contactless power transfer systems are desirable having more compact and lightweight for electric vehicles (EVs) recharging. A transformer of the system was developed according to the criteria of having high efficiency, a large air gap, and good tolerance to misalignment. The transformer uses series and parallel capacitors with rectangular cores and double-sided windings, with the size of 240 mm×300 mm×40 mm, the gap length of (70 ± 20) mm, the misalignment tolerance in the lateral direction of ± 125 mm, and the secondary mass of 4.6 kg. The characteristics of the system were studied with a charge control circuit and lead acid batteries being connected to the secondary winding. The results show that an output power of 1.5 kW and efficiency of 95% was achieved in the normal position and that the system has acompact-structure, light-weight, and satisfies the above criteria.