A new postfault operation method for three-level neutral-point-clamped inverters

The possibility of the postfault operation for three-level inverters is crucial to avoid severe damage to the equipment, downtime of technological process, and consequent economic harm. In this paper, a new postfault operation control algorithm based on space vector pulse width modulation with the balanced capacitor’s voltage is proposed. This method provides comprehensive treatment for operations after all possible faults. The feasibility of the proposed control method is verified by simulation of one fault scenario in a three-level neutral-point-clamped inverter working with a 5 HP motor load.