A Robust Multilevel Inverter Topology for Operation under Fault Conditions

Multilevel inverters (MLIs) are used on a large scale because they have low total harmonic distortion (THD) and low voltage stress across the switches, making them ideal for medium- and high-power applications. The authenticity of semiconductor devices is one of the main concerns for these MLIs to operate properly. Due to the large number of switches in multilevel inverters, the possibility of a fault also arises. Hence, a reliable five-level inverter topology with fault-tolerant ability has been proposed. The proposed topology can withstand an open-circuit (OC) fault caused when any single switch fails. In comparison to typical multilevel inverters, the proposed topology is fault-tolerant and reliable. The simulation of the proposed topology is conducted in MATLAB-Simulink and PLECS software packages, and the results obtained for normal pre-fault, during-fault, and after-fault conditions are discussed. Experimental results also prove the proposed cell topology's robustness and effectiveness in tolerating OC faults across the switches. Furthermore, a thorough comparison is provided to demonstrate the proposed topology's superiority compared to recently published topologies with fault-tolerant features.