Open-circuit fault detection and localization in five-level active NPC converter

In this paper a novel and fast open-circuit fault detection and localization method is proposed for Five-level active-neutral-point-clamped (5L-ANPC) converter. The method is based on comparing the measured output voltage with the reference voltage and the voltage obtained from the fault analysis. The implementation scheme of the method is presented; and all the practical aspects including capacitors voltage ripple and system delays are considered. The implementation of the method needs no additional sensor, measurement and processor board. The performance of the proposed method is verified by numerical simulation of a five-level converter. The results confirm the effectiveness and accurate operation of the method for fault detection and localization.