Fault-Tolerant Operation Strategy for Reliability Improvement of a Switched-Capacitor Multi-Level Inverter

The necessity of using several components in multilevel inverters jeopardizes the reliability of their operation. Hence, the aim of this article is to propose a novel single-phase fault-tolerant topology based on a switched-capacitor concept to ensure the robustness of the converter in the occurrence of a fault. The proposed single-source converter steps up the input voltage seven times with a simple control strategy. Fault tolerance of the converter is achieved by considering multiple fault cases and providing several redundant switching schemes concerning the type and location of failure. Each switching scheme is designed in a way to ensure the tolerability to both single and multiple open-/short-circuit failures. Also, self-voltage balancing of the capacitors, as well as the same amount of voltage levels and amplitude in the output, is guaranteed. Experimental analysis is carried out, and the results confirm the viability of the proposed inverter under normal and postfault operating modes.