Study of an Electric Vehicle WPT System with Ring-Series Passive Magnetic Shielding Based on Dual Transmitting Coils

In the design of wireless power transfer (WPT) systems for electric vehicles, minimizing magnetic leakage while maintaining high transmission efficiency is a challenging problem. To this end, a novel structure featuring dual transmitting coils and a ring-series magnetic shielding coil (RMSDT) is proposed to reduce magnetic leakage during system charging, thereby enhancing system safety performance. Additionally, the Particle Swarm Optimization (PSO) algorithm is employed to optimize system parameters, aiming to achieve high transmission efficiency while maintaining low magnetic leakage. To validate the effectiveness of the proposed design, a shielded WPT system for electric vehicles has been developed. Its performance is verified through a combination of experiments and simulations. The results demonstrate that the PSO algorithm significantly enhances transmission efficiency compared to traditional optimization methods. At an output power of 3.7 kW, the peak transmission efficiency exceeds 95%, representing an improvement of 4.63% compared to the conventional for-loop algorithm. Furthermore, the leakage magnetic field of the RMSDT structure in the target region is only 16.08 mu T, which is effectively reduced by 41.8% compared to the conventional WPT structure and sacrifices only 0.21% transmission efficiency. In summary, this paper can provide some references to the safety and efficiency of electric vehicle WPT.