A fault-tolerant strategy based on Fundamental Phase Shift Compensation for three phase multilevel converters with quasi-Z-source networks

This paper proposes a new fault-tolerant strategy for a multilevel converter (MLC) with an integrated impedance-source network. The proposed fault-tolerant strategy leverages the flexibility provided by the impedance-source network to implement the Fundamental Phase Shift Compensation (FPSC) method in order to restore operation of a multilevel converter with one or more faulty switches to the pre-fault conditions. In this paper, first a brief review of CHB converters and the modulation method is provided. Then the proposed fault-tolerant scheme is introduced. Finally, the experimental results from a prototype converter are provided to validate the operation of the proposed strategy.