Combination of three‐coil and LCC‐S structures for misalignment tolerance in wireless charging system with load‐independent output

Abstract

SummaryMisalignment tolerance is an important issue for the electric vehicle wireless charging system. This letter proposes a hybrid topology of the inductor–capacitor–capacitor‐series (LCC‐S) and three‐coil structures with load‐independent output to achieve misalignment tolerance, which is suitable for anti‐offset in the door‐to‐door direction of electric vehicles. The unipolar coil is divided into two windings to form the two coils in the three‐coil structure. The bipolar coil is employed as the transmitting coil of the LCC‐S topology, realizing decoupling from the two unipolar windings of three‐coil structure. The receiving coil only consists of a unipolar coil. From the central to the boundary positions, the output power of the three‐coil structure decreases while that of the LCC‐S topology increases. In this way, the output power can be stabilized against misalignment. Compared with existing hybrid topologies with two sets of coils, the receiver side adopts only one receiving coil and one compensation, which is compact, low‐profile, and cost effective. Besides, the output voltage is independent of the load, and the system can achieve constant voltage output characteristic. The experimental results validate the proposed system.