Magnetically coupled resonance wireless power transmission technology (MCR-WPT), as a technological innovation in the electric vehicle industry, is of great significance to promote the development of the electric vehicle industry chain. The current wireless charging technology is affected by the design of the vehicle itself, the distance between the vehicle-mounted part of the wireless charging and the ground is not fixed. And the changeable parking attitude will cause the projection of the transmitting coil and the receiving coil to deviate. Therefore, reasonable matching of transmission frequency, matching impedance and other parameters is of great significance for optimizing power transmission efficiency. This paper establishes a mathematical model of transmission frequency, matching impedance, distance between two coils and wireless power transmission efficiency. Based on the preliminary analysis of 10 experimental data of wireless charging in the laboratory under different coil spacings, the relationship between various parameters and wireless charging efficiency is obtained. In view of the problem of coil offset under actual charging conditions, a nonlinear optimization model for maximizing the efficiency of the MCR-WPT system is proposed. The selected optimization parameters are parameters such as transmission frequency and matching impedance. The goal is to ensure the maximum value of automotive coil offset under high transmission efficiency. In this paper, the optimization model is solved based on the Ant lion optimizer, and the optimal parameter values under the specified working conditions are obtained, and the relative error is less than 3%. When the coil spacing is 10mm, the maximum offset of the coil with a transmission efficiency higher than 80% is 0.3423m, and the RMSE between theoretical and experimental results is less than 0.015. Algorithm optimizes the power transmission efficiency and improved the fault tolerance rate of wireless charging system during parking.
