Phase shift investigation of dual-three phase V-shaped PM vernier motor for improving torque and power factor

Abstract

Permanent magnet vernier motor (PMVM) is extremely attractive in low-speed large-torque, whereas it always suffers from poor power factor. In order to realize the cooperative improvement of torque and power factor, this paper applies dual-three phase winding in PMVM, and investigates the influence of phase shift on torque and power factor improvement from the perspective of working harmonics and non-working harmonics. The key of this paper is to decompose the armature field harmonics. Through appropriated phase shift, increasing the armature working harmonics to improve the torque, and eliminating the armature non-working harmonics to enhance the power factor. Then the 24/38 DTP-PMVM is designed. Through theoretical derivation and simulation, it is verified that the DTP-PMVM torque is optimal and power factor is improved by phase shift 30°, compared with phase shift 0°.