Fault-Tolerant Analysis-Based Performance Assessment of Single-Phase Multilevel Inverter Topologies With Reduced Switch Count

Over the last several years, there has been significant emphasis on the study of multilevel inverters (MLIs) within the field of power electronics. MLI is often preferred over traditional 2L inverters owing to its enhanced performance characteristics. Various MLI architectures have been developed in recent years, each using a different set of components to provide a distinct voltage level across load terminals. MLIs are vulnerable to several types of faults due to a higher number of components and subassemblies. The fault-tolerant (FT) ability of the topologies is very crucial for the reliable operation of the overall system. This article provides a study of the FT ability of different types of MLIs. In the analysis, switch and source faults (SFs) have been considered with different fault categories. Single switch, combinations of two switches, and SFs have been analyzed. A comparison of different fault indices has also been provided, which guides the direction of future research in the field of FT MLIs. Experimental validations for highlighting the usefulness of the FT analysis for two common types of topologies widely used have been carried out for various types of faults and test results are provided.