Fault-tolerant operation of cascaded H-Bridge inverters using one redundant cell

Abstract

This paper presents a fault-tolerant technique for multilevel Cascaded H-Bridge (CHB) inverters. A faulty power switch in high power converters can lead to expensive downtime, loss of productivity, and increased costs. In the event of a fault, the defective cell is bypassed and a backup H-Bridge cell is replaced to generate balanced line-to-line voltages. Using the remaining cells, CHB inverter will operate with maximum achievable output voltage. Simulation results are offered for a seven-level CHB inverter to validate the proposed fault-tolerant technique.