Highly Resilient Fault-Tolerant Topology of Single-Phase Multilevel Inverter

摘要

The high failure rate of semiconductor devices and capacitors, matched with their high requirement in the architecture of a multilevel inverter (MLI) topology, results in low reliability of the inverter. A low device count, preserving the output power upon fault occurrence and the ability to tolerate both open- and short-switch failures on all fault locations, handling both single- and multiple-switch failures, and achieving natural voltage balancing of the capacitors, are the main challenges for the existing solutions to the fault-tolerant topologies. Thus, a highly resilient fault-tolerant topology, based on conventional inverters, is proposed in this article. The proposed solution accomplishes all the aforementioned challenges without deteriorating the efficiency of the inverter during faulty conditions. The robustness and effectiveness of the proposed topology are verified by the obtained experimental results. Multiple cases of switch failure are considered to cover all fault locations and types. Comparative analysis with the recently proposed fault-tolerant topologies on MLIs shows the superiority of the proposed topology over the rest.