Development and experimental validation of fault detection and diagnosis method in SPWM modulated symmetric cascaded H-bridge multilevel inverter

Abstract

This paper discusses gate open-circuit fault detection and diagnosis method in SPWM modulated symmetric cascaded H-bridge multilevel inverter. First, an output voltage modelling under fault condition in cascaded H-bridge multilevel inverter is presented. Further, simulations of fault conditions have been carried out for the development of the fault detection and diagnosis method. Based on fault modelling and simulations, a fault detection and diagnosis method have been proposed based on the mean values of the bridge voltages as the diagnostic feature. Further, the proposed method has been validated experimentally on a 5-level symmetric sine pulse width modulated cascaded H-bridge multilevel inverter.