Development and experimental evaluation of a single-winding, dual-stator, spoke-array vernier permanent magnet machines

A dual-stator spoke-array (DSSA) vernier permanent magnet (VPM) machine has been proved to be high torque density and power factor in the previous paper. However, Inner stator thermal issues could be a concern for the DSSA VPM machines, and the inner stator cooling structure is complex. This paper proposes a single-winding, dual-stator, spoke-array (SDSSA) VPM machine. The double-sided machine with only single-side winding configuration makes the DSSA VPM machine free from the thermal issue of inner stator winding. Detailed structure features and experimental tests, such as inductance, back EMF waveforms, torque vs current and so on, of the SDSSA VPM machine are presented. It is shown that torque density and power factor of the SDDSA VPM prototype with less than 3A/mm² are larger than 65kNm/m³ and 0.78, respectively while the torque per magnet mass is almost 120 Nm/kg. Finally, this paper proposes the comparison of experimental tests on the DSSA and SDSSA VPM prototypes.