Design of Coil Structure for Anti-Offset and Highly Efficient Wireless Power Transfer

In this paper, a coupling coil structure suitable for wireless charging of electronic equipment is designed. The coil is designed with PCB. The structure comprises an 8-shaped receiving-transmitting coil and two relay resonance coils on the same plane. When multiple transmitter coils are arranged in a row, the mutual inductance remains relatively constant during the offset process of the load coil, which can effectively reduce the power fluctuation during the charging process. Three-dimensional finite element simulation analysis and experiments were performed on the system under the conditions of alignment and offset, Experimental results show that when the coils are well aligned, the proposed wireless power transfer (WPT) system can achieve a peak efficiency of 92.7%.