Exposure Assessment of a 20-kW Wireless Power Transfer System for Electric Vehicles

Wireless power transfer technology is essential for autonomous electric vehicles. Electric vehicles demand increasingly higher power outputs. Therefore, it is necessary to study the harmfulness of human body exposure to electromagnetic waves generated in a wireless power transfer system. This study provides exposure assessment for a 20-kW wireless power transfer for electric vehicles. The electromagnetic field distribution of a 20-kW wireless power transfer system is analyzed for the two cases where the transmitting and receiving pads are aligned with the small gap and not aligned with the large gap, and compared with the results of the experimental measurements. Moreover, when the system (not aligned with the large gap) is installed in an electric vehicle, analysis of the exposure is carried out. Finally, dosimetry is performed on the exposure scenario in which the human body is placed around the vehicle, and the induced values inside the human body are compared with the internation guidelines. As a result, the induced values exceed the basic restrictions for the fat and the muscle of the human body, but not for the central nervous system.