Research on Wireless Charging Localization System for Electric Vehicles Based on Auxiliary Coil

Wireless charging for electric vehicles, which provides a new idea to solve the mileage anxiety of electric vehicles, has received wide attention from the industry. However, in practical applications, the misalignment between the transmitting and receiving coils of the wireless charging system will lead to a decrease in transmission power and efficiency. The detection coil method, with its simple, reliable and low-cost features, has become a feasible way to realize the positioning of wireless charging systems. Aiming at the common DD/DD coupling mechanism, this paper proposes a detection coil set consisting of four helical coils to realize the receiving coil misalignment detection. The design is optimized by decoupling the helical coils from the receiving coils to reduce interference. With the stable magnetic field generated by the transmitter coil, the detection coil generates an induced voltage, and the positioning of the detection coil is realized by fitting the curve of the induced voltage with the misalignment. The feasibility of the proposed method is verified by theoretical simulation.