Investigation on sensorless operation of two new fault-tolerant interior permanent magnet motors with trade-off of fault tolerance and flux-intensifying effects

Abstract

In this paper, two new fault-tolerant interior permanent magnet (FT-IPM) motors are proposed and compared for achieving high fault tolerance and sensorless operating capacity under multiple operations. Most previous studies regarding FT-IPM motors aim to improve fault-tolerant capability but suffer from the saliency characteristic problem, which is unfavorable for sensorless control. To overcome this issue, the design idea of flux-intensifying effect is innovatively proposed. Based on this, two new FT-IPM motors with different rotor structures and slot-pole combinations are developed to achieve flux-intensifying effect. To explore the impact of different motor structures and slot-pole combinations on motor performances, the simulation and experimental results of the two motors are compared and discussed in detail. The comparison results indicate that good fault tolerance and sensorless operating performances need tradeoffs, which provide a reference for balancing the fault tolerance and sensorless operating capacity.