Comparative study of stator consequent‐pole permanent magnet machines

Abstract A comparative investigation is made of stator consequent‐pole (SCP) machines with different permanent magnet (PM) arrangements. Compared with conventional surface‐mounted PM (SPM) configurations, SCP configurations produce more orders of air‐gap field harmonics. Due to asymmetrical PM magnetomotive force (MMF) distributions and the double‐side slotting effect, SCP machines exhibit multiple air‐gap field harmonics, especially relatively enhanced low‐order field harmonics, for torque production. As a consequence, improved torque capability can be obtained over that of conventional SPM counterparts. Machine topologies and operating principles are described. The design parameters of four SCP machines with different magnet arrangements are globally optimised. The key electromagnetic performances, including open‐circuit performance, torque quality, field‐weakening capability, and efficiency, are comprehensively investigated and compared by the finite element (FE) method. Finally, some experimental measurements on an optimally selected SCP machine prototype are carried out to validate the theoretical and FE analyses.