Coupler Loss Analysis of Magnetically Coupled Resonant Wireless Power Transfer System

The demand for electric vehicles has increased over the past few years. Wireless power transfer for electric vehicles provides more flexibility than traditional plug-in charging technology. Charging couplers are critical components in wireless power transfer systems. The thermal effect produced by the magnetic coupler in work will cause the temperature of the device to rise rapidly, affecting the work efficiency, transfer power, operation reliability, and service life. This paper modeled and analyzed each component's temperature distribution characteristics and thermal behavior. Firstly, the magnetic coupler's mutual inductance and magnetic circuit model are established, and the thermal model of the magnetic coupler analyzes the heat generation process. The thermal models of the coupler under three different magnetic core distributions are established, and the temperature rise of each component is obtained. The temperature rise of different parts of the coupler is verified by the temperature rise test structure of the experiment.