An inductive charger with a large air-gap

This paper describes a new inductive charger circuit for opportunity charging of electric vehicles in the future. The coupling transformer utilized features a very large air-gap that is comparable to the cross-sectional dimensions and hasn´t been considered in previous studies. The study proposes to fully compensate the large leakage inductance of the windings using series capacitors and to control the charging power using an additional DC-DC chopper at the output stage. The eddy current losses associated with the leakage flux and voltage stresses in the circuit are shown to be acceptable. The working principle of the proposed circuit is experimentally tested.