Integrated Four-LCC-Parallel Circuit for Wireless Power Transfer of Electric Vehicles with Vector Synthesis Strategy

Misalignment tolerance is an indispensable characteristic in wireless power transfer (WPT) systems for electric vehicles (EVs). In this paper, a multiple Tx parallel topology with a vector synthesis strategy is proposed to achieve misalignment tolerance for unipolar (Q) coil over the X and Y misalignments. The coils and compensation inductances at the Tx side are highly integrated. After modification of the phase angles of the four half-bridge inverters based on the strategy under misalignments, the output voltage fluctuation can be decreased. The mathematical model of the proposed four-LCC-parallel topology is established and the vector synthesis strategy is explained. The magnetic couplers and the design principle are presented. A 2-kW prototype is built to verify the proposed system. the output voltage fluctuation of the experiment under misalignments is less than 3.1%, and the average dc-dc efficiency is 87.5%.