A New Fault-Tolerant MLI—Investigating Its Skipped Level Performance

Abstract

Generating higher voltage levels with fewer power electronic components and fault tolerance is a challenging issue for multilevel inverters (MLIs). In this article, a new generalized fault tolerant MLI (FTMLI) with reduced semiconductor switches is presented. The proposed FTMLI topology contains more redundant switching states; thus, the topology can tolerate faults in both switches and/or sources. This article also introduces the new level shifted carrier pulsewidth modulation technique in effective utilization of abnormal voltage level combinations (or skipped voltage level) for running emergency loads. The proposed topology's operation is discussed along with the fault-tolerant capability for both the symmetric and asymmetric modes. Experimental results are presented to show the effectiveness of the FTMLI topology using the associated control strategy. A comparative analysis between the proposed topology and other MLI topologies is also provided to highlight the proposed topology's merits.