Abstract:The inductive power transfer (IPT) technology applied in electric vehicle charging is widely studied because of its features such as safety, reliability, flexibility, and convenience. The loosely coupled transformer usually has a large leakage inductance, thereby significantly reducing the transformer's coupling coefficients and the system's power transfer capability. When there is misalignment on the primary and secondary sides of the transformer after the parking of an electric vehicle, this characteristic is especially obvious. The design of an IPT system with high misalignment tolerance is proposed, in which the loosely coupled transformer combines the coupling characteristics of solenoidal and bipolar coil structures, thus realizing a wider misalignment tolerance range. In addition, the circuit topology condition that matches the transformer structure is given, and the system output characteristics with various compensation topologies on the primary and secondary sides and various output connection modes are analyzed and summarized. The transformer's coupling characteristics with and without misalignment were simulated using a 3D finite element modeling tool, and they were further experimentally verified on a 3 kW experimental platform with a 200 mm air gap.