Misalignment Tolerance of Electric Vehicle Wireless Charging System Based on Reconfigurable Adaptive Topology and Centrosymmetric Coils

In wireless power transfer systems for electric vehicles, coil misalignment is inevitable in most charging situations. Most present studies concentrate on the misalignment tolerance in one direction, either in the X, Y, Z, or diagonal directions, but lack the misalignment tolerance on the whole charging plane. In this article, a reconfigurable adaptive topology and centrosymmetric coils are proposed to achieve misalignment tolerance over the whole charging plane. By switching among three operation modes of the proposed reconfigurable topology at the different misaligned regions, the output voltage at the boundary regions can be increased and the output voltage fluctuation can be limited. First, the mathematical model of the proposed reconfigurable adaptive topology in the different operation modes is investigated. Second, the design process of the magnetic coupler and the characteristics of the centrosymmetric coils are presented. Finally, a 926-W prototype is built to verify the proposed system. The experimental results demonstrate that the fluctuation of the output voltage is less than 21.3% apart from the four most corner regions, and the peak efficiency is 84.5%.