Free space wireless charging in cars with fishbone DQ IPT coils

Abstract

A new free space wireless charging system for inner vehicle use with a ferrite-core fishbone architecture is proposed in this paper. This system achieves wireless charging independent of the position and direction of its receiving side by means of two transmitting coils installed in one ferrite core structure. These direct (D) and quadrature (Q) coils generate a uniform rotating magnetic field inside the vehicle. In the proposed system, a double-sided LCC circuit topology is applied to each of the D and Q coils to provide load-independent current sources. The parameters of the LCC compensation circuits are determined to guarantee zero voltage switching for the switches of the high-frequency inverter and to limit the inverter output current simultaneously. A detail analysis of the operation and design of the proposed system was carried out, and its feasibility was verified with experiments for 1 W level of power receiving within 30 cm distance between transmitting and receiving coils at 280 kHz.