Novel design of a variable reluctance permanent magnet machine with bipolar coil flux-linkage

This paper proposes a novel design concept for variable reluctance permanent magnet machines (VRPMMs) by introducing heteropolar dual stators and shifted rotors in axial direction. The machine is geometrically similar to switched reluctance machines, but with homopolar PMs alternately mounted on stator poles. With this design concept, the bipolar and sinusoidal coil flux-linkage can be obtained due to the elimination of even harmonics between two axially parallel sub-machines. In addition, this design can offer another merit of torque density improvement. The machine topology features and harmonic cancellation theory are addressed. Then the electromagnetic characteristics of the 6/4-pole machine with the proposed design concept are investigated and compared with those of the original VRPMM. The detailed analysis results and experimental validation will be presented in the full paper.