New Flux Intensifying Technique for Five-Phase Fault-Tolerant Interior Permanent Magnet Motors Under Multiple Sensorless Operation

Due to the strict constraints with winding structures and slot-pole combinations of the conventional fault-tolerant interior permanent magnet (FT-IPM) motors, the desired sensorless operating performance is difficult to be implemented. Hence, this article proposes a new five-phase flux-intensifying FT-IPM motor with the characteristics of obvious and stable inverse saliency (L-d > L-q) considering multiple sensorless operating conditions. Correspondingly, in this article, the design concept of "flux-barrier guidance" is innovatively put forward and a novel motor structure is laid out with improved fault-tolerance and sensorless operating capacity simultaneously. First, the new slot-pole combination (20-slot/12-pole) is proposed from the perspective of flux intensifying. Second, by subtly setting q-axis asymmetric flux barrier, and improving air gap waveform, the superior inverse saliency characteristic is obtained, which effectively improves the sensorless operating performance. Finally, through simulation analysis and experimental tests, the rationality and validity of the proposed motor are verified.