ARCPI resonant snubber for the neutral-point-clamped inverter

This paper reports a resonant snubber for the neutral-point-clamped (NPC) i nverter using the auxiliary resonant commutated pole inverter (ARCPI) techn ique. The proposal guarantees zero-voltage switching of the main switches a nd zero-current switching of the auxiliary switches without incurring any v oltage or current spikes across or through the main switches and without be ing subjected to any modulation constraints. The operation principle of the ARCPI NPC inverter is illustrated. A simple method dealing with the static overvoltage problem of the inner switches is described. Commutation durati ons and current stresses in the basic ARCPI circuit are analyzed. The resul ts enable mathematical understanding and practical designing of the basic A RCPI circuit, In particular, the self-balancing quality and controlling pos sibility of the de center potential in the basic ARCPI circuit are investig ated, The proposal is verified by a 3-kW half-bridge ARCPI NPC inverter lab oratory prototype.