Systematic investigation on the effects of tracks’ mutual coupling on a GaN-based three-level bridge leg

An investigation of the mutual coupling among key switching paths in a three-level bridge leg based on GaN switches is presented in this paper. The used methodology relied on Ansys extensive numerical simulations based on the real printed circuit board (PCB) geometry. Results showed that the self-inductance is not enough to evaluate the switching behavior during some critical switching patterns. Further investigations highlighted that mutual coupling between power and gate-return paths plays a key role. The effect on the switching energy is shown to be up to 13 % in the worst-case scenario, i.e. at 400 V voltage and 7.5 A current.