Design of a Three-Phase Inductive Power Transfer Coil with Interphase Mutual Inductance Reduction

Inductive wireless power transfer (IPT) has brought convenience to many aspects of human life. Three-phase IPT has been proven with better performance in high-power applications. Three-phase IPT coil design is necessary to optimize the power transfer capability and efficiency. Also, interphase mutual inductance in three-phase IPT coils has been considered a problem. This paper analyzed the effects of the interphase mutual inductance using the phasor diagram approach. Two different cases with different coil structures have been discussed. A new three-phase IPT coil is proposed in this paper. With overlap coils in the center of the ferrite core, the proposed coil achieves very low interphase mutual inductance. A comparative study has been done for both the proposed coil and a regular unipolar coil. Simulation results show that the proposed coil has better power transfer capability than the regular unipolar coil.