Impact of Postfault Flux Adaptation on Six-Phase Induction Motor Drives With Parallel Converters.

The redundancy of multiphase drives provides an inherent fault-tolerant capability that is appreciated in applications with a complicated corrective maintenance or safety-critical requirements. Fault restrictions, however, force the system to be reconfigured to operate in a smooth and efficient manner. Previous works have been focused on the optimization of current waveforms to generate an undisturbed operation but still maintaining the prefault rated flux settings. This study shows that efficient controllers can improve the postfault performance in six-phase induction machines supplied by parallel-connected converters if offline optimization is used to obtain a variable reference flux. Theoretical and experimental results confirm that the proposed flux adaptation method provides higher torque/power capability, lower degree of imbalance in the current sharing between windings and efficiency improvement. [ABSTRACT FROM AUTHOR]