Unbalanced Selective Harmonic Elimination for fault-tolerant operation of three phase multilevel Cascaded H-bridge inverters

Abstract

This paper proposes a new modulation method for balanced operation of a multilevel inverter with a faulty switch. This modulation method is based on Selective Harmonic Elimination (SHE) and can be implemented in different multilevel topologies, primarily in Cascaded H-bridge (CHB) inverters. In this paper, first the general concept of SHE is explained briefly. Then, the proposed switching strategy for fault-tolerant operation of a CHB with one faulty switch is presented. Finally, experimental results are provided to validate the proposed switching.