Multi-objective optimization and electromagnetic compatibility design of the coupling mechanism in Dynamic wireless charging systems

To enhance the endurance and charging convenience of electric vehicles during driving, Dynamic Wireless charging (DWPT) technology has become a current research hotspot. However, the design of the coupling mechanism in this system is confronted with the performance trade-off between transmission efficiency and electromagnetic compatibility (EMC). This paper aims at the parameter coupling problem of the key coupling structure in the DWPT system and proposes a multi-objective optimization method based on NSGA-II, aiming to simultaneously optimize the energy transmission efficiency and electromagnetic leakage level, and designs a magnetic shielding module that takes into account both shielding effectiveness and structural compactness. Firstly, a three-dimensional finite element model was established based on ANSYS Maxwell, and the transmission performance of the typical double D-coupled coil structure under different horizontal/vertical offsets was analyzed. The simulation results show that under the conditions of a 20 cm spacing and ±10 cm lateral offset, the system transmission efficiency has been optimized from the original 78.2% to 87.6%. The magnetic leakage intensity was reduced from the original maximum value of 1.35 μT to 0.47 μT, meeting the far-field interference requirements of the CISPR 11 standard. Secondly, a multi-objective optimization model with the goals of maximizing transmission efficiency, minimizing leakage magnetic field and reducing coil volume was constructed. The balanced Pareto optimal solution set was obtained by using the NSGA-II algorithm, and the special-shaped ferrite magnetic shielding structure was designed based on the principle of guiding magnetic flux path. Finally, physical verification was carried out on the constructed 1:2 scale experimental platform. The experimental results are consistent with the simulation trend. The optimized structure maintains an average transmission efficiency of 86.1% under the rated power of 3.3 kW, and the near-field flux leakage is controlled within 0.52 μT. Studies show that the multi-objective optimization method and electromagnetic shielding design proposed in this paper can significantly improve the comprehensive performance of the DWPT system, and have good engineering practicability and promotion value.