A Unified Analysis of the Fault Tolerance Capability in Six-Phase Induction Motor Drives

Abstract

The fault tolerance of electric drives is highly appreciated at industry for security and economic reasons, and the inherent redundancy of six-phase machines provides the desired fault-tolerant capability with no extra hardware. For this reason some recent research efforts have been focused on the fault-tolerant design, modelling and control of six-phase machines. Nevertheless, a unified and conclusive analysis of the post-fault capability of six-phase machine is still missing. This work provides a full picture of the post-fault derating in generic six-phase machines and a specific analysis of the fault-tolerant capability of the three mainstream six-phase induction machines (asymmetrical, symmetrical and dual three-phase). Experimental results confirm the theoretical post-fault current limits and allow concluding which is the best six-phase machine for each fault scenario and neutral arrangement.