Optimal Fault-Tolerant Control of Six-Phase Induction Motor Drives with Parallel Converters

Abstract

Multiphase drives and parallel converters have been recently proposed in low-voltage high-power applications. The fault-tolerant capability provided by multiphase drives is then extended with parallel converters, increasing their suitability for safety-critical and renewable uses. This advantageous feature, compared to standard threephase drives, has been analyzed in the event of open-phase faults. However, when using parallel converters, a converter fault does not necessarily imply an open-phase condition, but usually just a limited phase current capability. This work analyzes the fault-tolerant capability of six-phase drives with parallel converter supply. Different scenarios considering up to three faults for single and two neutral configurations are examined, optimizing off-line the post-fault currents and modifying accordingly the control strategies. Experimental results confirm the smooth transition from pre- to post-fault situations and the enhanced post-fault torque capability.