Design and Optimization of Inverse Edge Overlapping Offset Resistant Structure to Improve Anti‐Offset Performance for Dynamic Wireless Charging of EVs

ABSTRACT For the electric vehicles dynamic wireless power transfer system in the coupling mechanism under the offset limit distance, there will be coupling coefficient fluctuation dramatically large, the limit offset distance is shorter, the anti‐offset performance is insufficient. Therefore, in order to achieve a quasi‐constant coupling coefficient and improve the limit offset distance and anti‐offset performance, this paper proposes a symmetric inverse edge overlapping offset resistant structure. First, a symmetric inverse edge overlapping offset resistant structure for dynamic wireless power transfer system is proposed, the quasi‐constant coupling coefficient characteristics of the structure are analyzed. Second, according to the calculation method of mutual inductance of rectangular coil based on vector potential, an optimization strategy based on the principle of minimizing the fluctuation of coupling coefficient is proposed, the coil parameters are optimized to meet the design requirements. Finally, a 1 kW experimental prototype is built to verify the anti‐offset performance of the proposed coil. The experimental results show that the coupling coefficient fluctuation rate is 3.79% when the coupling mechanism is offset by 21 cm from the vehicle driving direction, the coupling coefficient fluctuation rate is 6.65% when the limit offset distance of 35 cm is reached. The transmission efficiency of the system is not less than 95.31%, which proves the reliability of the structure and the effectiveness of the optimization method.