Examination of Coil Resistance Measurement during Wireless Power Transfer and Validity of Calculation by Finite Element Analysis

Abstract

This paper describes a method for measuring the ac resistance of sending and receiving coils during wireless power transfer. This method focuses on the ratio of the input voltage to the coil current. The coil resistances measured by this method were compared with the calculated values obtained by finite element analysis. Further, the validity of the measurement and calculation for the coil constants were examined by solving simultaneous equations for sending and receiving coil current for an equivalent circuit for a wireless power transfer system and obtaining the input and output power and power transfer efficiency.