Analysis of Magnetic Field Emissions in Inductive Power Transfer EV Chargers Following Reference Designs in SAE J2954/2019

This paper aims to investigate the radiated magnetic field by 11 kW inductive power transfer (IPT) systems used for the charging of electric vehicles. Two reference designs suggested by SAE J2954 are studied. Both designs are analysed to obtain the coils winding currents, and 3D FEM models are built in COMSOL without considering the car chassis, which constitutes a conservative approach. The magnetic field intensity at specific distances from the IPT coupler are calculated. Finally, the simulation results are compared with the respective magnetic field limits defined in the international standards SAE J2954, IEC 61980-1 and ICNIRP. The results show that the magnetic field radiations at 10 meters points are significantly lower than the limits established in the SAE J2954, while the emissions at 0.9 meters points are only slightly below the limits defined by ICNIRP.