A Novel Fault-Tolerant Single-Phase Multilevel Inverter for Reliable UPS Applications

In this work, a multilevel inverter with the feature of single and multi-switch fault-tolerant capability is proposed for ensuring uninterrupted power supply in emergency load applications. By integrating a redundant unit into the multilevel inverter, the converter tolerates faults effectively in both symmetrical and asymmetrical voltage modes. To demonstrate the converter's robust performance, experimental validation on a 500 W prototype is done under various faulty and dynamic conditions. Additionally, the paper includes the reliability and efficiency analysis of the proposed converter. Further, a new parameter is introduced in this work to evaluate the faulttolerant capability of the converter topologies, offering deeper insights into its reliability. A comparative analysis is finally presented to emphasize the advantages of the proposed topology in terms of various performance matrices.