A large air gap 3 kW wireless power transfer system for electric vehicles

A wireless power transfer system for electric vehicles is required to have high efficiency, a large air gap, and good tolerance for misalignment in the lateral direction and to be compact and lightweight. A new 3 kW transformer has been developed to satisfy these criteria using a novel H-shaped core and split primary capacitors. The design procedure based on the coupling factor k, the winding´s Q, and the core loss is described. An efficiency of 90% was achieved across a 200 mm air gap.