Characteristic and Control Strategy Study of Electromagnetic Coupling Mechanism among EV Wireless Charging system

In order to maximize the transmission efficiency of wireless electric vehicle (EV) charging system, transmitter coil and receiver coil are generally assumed to be coaxial perfectly aligned. However, offsets often exist between transmitter coil and receiver coil both in design and in implementation, which would lead to the drop of system efficiency. Based on the mutual inductance circuit model, this paper analyzes the reasons of the system efficiency decrease, and verifies it by using the finite element simulation software. To solve this problem, a frequency adaptive tracking system including power detection circuit, the wireless signal transmitting and receiving modules etc is designed. Finally, the correctness of theoretical analysis is verified by the experiment of static wireless electric vehicle charging. The results indicate that the frequency adaptive tracking system is effective, which in turn promotes the theoretical studies of wireless charging electric vehicle.