Impact Investigations and Characteristics by Strong Electromagnetic Field of Wireless Power Charging System for Electric Vehicle Under Air and Water Exposure Indexes

Our research team has been developing a wireless power charging (WPC) system for electric vehicle (EV) using superconducting and normal conducting resonance coils in order to improve the transfer efficiency and stability. In the practical approach, the EV, which is installed outside, is wirelessly charged without moving. The antenna (Tx) coil is disclosed by rain or snow and so on. From this reason, the transfer characteristics surrounded by water circumstance, i.e., fresh water or salt water, should be evaluated to commercialize In addition, the high-voltage WPC system generates strong electromagnetic fields (EMFs) around Tx and receiver (Rx) coils. As the human safety with respect to EMFs is an important measure, it is required to identify the condition under which human exposure complies with the safety regulations. Thus, in this paper, as a fundamental approach, the spatial spots of current around Tx and Rx coils were measured. As well as, the transfer efficiencies of a WPC unit under different water circumstances of Tx and Rx coil were measured with an RF generator of power of 150 W, 370 kHz.