Design of a Low-Cost PM Vernier Machine with Improved Electromagnetic Performance

By utilizing various design techniques this paper aims to improve the electromagnetic performance of a ferrite based consequent pole PM Vernier machine (CP-PMVM). CP-PMVM with thick ferrite PMs offers considerable reluctance torque while having the advantage of reduced PM cost. However, CP structure suffers from the torque ripple issue, moreover its power factor is exceptionally low. Those issues can be resolved by adapting various design techniques such as controlling the, stator / rotor tooth fillet, symmetric / asymmetric PM pole arc ratio / PM thickness, flux gaps in stator. Mostly, various design techniques have contradictory effects on the electromagnetic performance thus improving the overall machine performance by having the best compromise is quite challenging. To demonstrate various aspects of the design problem, the detailed electromagnetic performance of a prototype CP-PMVM with variation of the key design parameters have been investigated in detail. The further extensions of the idea will be detailed in the full paper.