Impact of switching frequency variation to the power transfer efficiency of wireless power transfer converter

This paper presents the impact of the switching frequency variation to the power transfer efficiency of a wireless power transfer converter. An experimental demonstrator is used to as a model for this study. The transmitter use Wurth Elektronik wireless power charging coils, 24μH, 10%, which is installed across the output of high frequency half-bridge inverter. The switching frequency is varied from 10kHz in steps of 10kHz until 100kHz. The distance between the coils is fixed at 10mm. The receiving coil is fed with a high frequency full-bridge rectifier and a DC load. Experimental results show that the power transfer efficiency varies when the switching frequency is increased. The power transfer efficiency reached its peak at 72% when the switching frequency is at 30kHz.