Soft-switched three-level capacitor clamping inverter with clamping voltage stabilization

This paper proposes a zero-voltage-switching scheme for the three-level capacitor clamping inverter. The proposed small-rating auxiliary circuit ensures not only zero-voltage switching of the main switches and zero-current switching of the auxiliary switches, but the clamping capacitor voltage of the inverter is also stabilized. The scheme prevents any voltage or current spikes from happening over the main or auxiliary switches and no modulation constraints are incurred. Operation, analysis, designing, and testing aspects of the scheme are detailed.