Electromagnetic safety of magnetic resonant wireless charging system in electric vehicles

With the increase in transmission power of the wireless charging system in electric vehicles, the magnetic field strength around the system tends to be larger, so it is increasingly necessary to evaluate the electromagnetic safety of the system. In this study, the electromagnetic safety in adult and child bodies exposed to a magnetic resonant WPT system in an electric vehicle is evaluated considering four exposure schemes. Three human body models and a real-size electric vehicle model are constructed. The transmission power and frequency are 10kW and 85kHz, respectively. Numerical computation with the finite element method is implemented. The results show the exposure limit can be generally satisfied in the adult body model standing behind the car and sitting in the driver's seat. While the induced electric field is in excess of the limit in small parts of the adult and child body models lying behind the car which are very close to the Litz wires of the WPT system. This paper offers a significant guideline for the selection of transmission power and the design of the system.