Modified reduced device multilevel inverter structures with open circuit fault-tolerance capabilities

Reliability and large number of components are major challenges for multilevel inverters being used in many industrial applications. These inverters may face situations like failure of power switches, which, in turn, can cause severe damage to other equipment of the system. Hence, it is important these inverters are fault-tolerant. In this article, some of the recently proposed reduced device multilevel inverter (RD-MI) topologies are considered and analyzed in light of imparting open circuit fault-tolerance capability. In RD-MIs, the occurrence of faults would cause a shutdown of the system due to the lack of redundant switching states. However, for the cases involving “any single open-switch failure (SOSF),” the system can continue to operate uninterrupted by imparting fault-tolerant (FT) feature to the RD-MIs. With the proposed solution, the complete system shutdown can be avoided, thereby achieving higher reliability. In this work, two RD-MIs are chosen to demonstrate the proposed approach. Further, the proposed FT RD-MIs based on suggested FT strategy under the healthy and abnormal modes are simulated using MATLAB/Simulink software. The obtained simulation results are experimentally validated.