Four-Leg-Based Fault-Tolerant Matrix Converter Schemes Based on Switching Function and Space Vector Methods

A four-leg-based fault-tolerant matrix converter topology is proposed, along with switching function and space vector approaches for modulation schemes, to improve the reliability of matrix converter drives. The four-leg-based fault-tolerant structure utilizes an additional redundant phase module. Based on the reconfigured hardware topology, fault-tolerant modulation strategies with both switching function and space vector approaches are developed to provide the matrix converter drives with continuous and disturbance-free operation. Pulsewidth-modulated algorithms with closed-form expressions, based on a switching function matrix, are presented to synthesize redefined output waveforms with reconfigured converter structures. Furthermore, a space-vector-based scheme using the indirect equivalent circuit with the fictitious dc link is also developed for the fault-tolerant topology after failures. Experimental results show the feasibility of the proposed four-leg-based fault-remedial approach, along with the developed modulation techniques.