Optimization of WPT-Based Snubber Circuit via Coupled-Mode Theory to Eliminate Switching Oscillations

This article introduces an innovative wireless power transfer (WPT) based snubber circuit designed to mitigate the switching oscillations of SiC MOSFET, caused by parasitic impedances in the switching circuit. The key innovation lies in artful transferring the oscillating energy to an optimally designed receiver through magnetic resonant coupling. It demonstrates that the switching oscillation time can be reduced by up to 67%. Compared to the conventional RC snubber, the WPT snubber significantly reduces permissible voltage and switching loss. This technology significantly decreases the size of passive components in the snubber circuit, leading to a substantial increase in power density. Lastly, an optimal design approach for WPT snubber parameters is proposed based on the coupling mode theory, eliminating the need for measuring parasitic parameters and mutual inductances of the circuit, as well as the need for complex mathematical calculations.