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

In this work, a multilevel inverter with the feature of single and multiswitch 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 article includes the reliability and efficiency analysis of the proposed converter. Furthermore, a new parameter is introduced in this work to evaluate the fault-tolerant 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.