Scaling Effect Analysis of Surface-Mounted Permanent Magnet Vernier Machine with Concentrated Windings

Surface-mounted permanent magnet vernier machines (PMVMs) have shown better average torque and reduced torque ripple compared to conventional permanent magnet synchronous machines (PMSMs) at the small-scale power rating. However, the torque performance of PMVM across the various power ratings is rarely studied. Also, for PMVMs, distributed windings can bring longer end winding length and higher copper loss, making the slot/pole number combination for concentrated windings essential. Thus, this paper aims to investigate the scaling effects of PMVMs and PMSMs with concentrated windings across different power ratings, ranging from W-class to kW and MW-class. First, the torque production mechanisms of PMVMs are analyzed. Next, the structural variables are optimized to ensure a fair comparison. Finally, the electromagnetic performance of both machines at power ratings of 100W, 10kW, and 1MW are comprehensively compared. The results indicate that PMVMs exhibit superior performance than PMSMs in W-class and kW-class, but fall short in MW-class.