A Numerical Method to Reduce the Stray Magnetic Field Around the Asymmetrical Wireless Power Transfer Coils for Electric Vehicle Charging

Wireless power transfer (WPT) is becoming increasingly popular in stationary electric vehicle charging. Unfortunately, the adverse health effects due to the stray magnetic field created by the WPT coils have increasingly caused concern. However, the traditional stray magnetic field optimization design method based on finite element simulation is time-consuming and resource intensive. In this paper, a numerical method to reduce the stray magnetic field around the asymmetrical wireless power transfer coils is proposed while maintaining the transmission power constant. The formulas of the stray magnetic field around the WPT coils are derived, and the distribution characteristics of the stray magnetic field are analyzed in detail. The stray magnetic field around the asymmetrical wireless power transfer coils is optimized by the numerical method, and the number of the turns for the WPT coils corresponding to the minimum stray magnetic field intensity is obtained. The effectiveness of the numerical method is verified via the finite element analysis tool JMAG, and it is proved that the numerical method require less computational time than the finite element simulation. The experiments have also been carried out to evaluate the validity of the theoretical analysis.

Automated summary

This paper proposes a numerical method to reduce the stray magnetic field around asymmetrical wireless power transfer coils and verifies its effectiveness. Experimental results show that the numerical method requires less computational time compared to finite element simulation.