A High Power Factor Vernier Machine with Coil-Pitch of Two Slot Pitches

In this paper, an 18-slot/26-pole Vernier permanent magnet synchronous machine (VPMSM) with coil-pitch of two slot pitches is proposed based on a 9-slot/18-flux-modulation-pole/26-pole VPMSM with concentrated tooth-coil windings. Compared with the original VPMSM, the number of slots is doubled and the phase winding connection is adjusted to reduce the space harmonic content, the phase inductance and hence, improve the power factor. The study shows that the proposed VPMSM has a higher power factor of 93% with a torque improvement. Moreover, a series of VPMSMs with high power factor is proposed from the same design principle.