Characteristics Analysis of a Novel 12/8 Double Stator Bearingless Switched Reluctance Motor

A novel 12/8 double stator bearingless switched reluctance motor (DSBSRM) is proposed in this paper. Unlike conventional BSRMs, the proposed motor is constructed of three parts: outer stator, inner stator and hybrid rotor. The outer stator has twelve stator poles, and the stator poles are divided into two types: exciting and auxiliary poles. The inner stator has four identical stator poles. The hybrid rotor is composed of rotor segments, nonmagnetic isolator and toroidal core. The rotor segments are embedded in the outside of the nonmagnetic isolator, and the toroidal core is embedded in the inside of the nonmagnetic isolator. Due to the special structure, the proposed motor operates in short flux paths, and the magnetic flux paths of the inner and outer stator are independent from each other. Therefore, compared with conventional DSBSRM, the proposed DSBSRM not only has better decoupling characteristics between torque and suspending force, which may reduce the control difficulty of the proposed structure, but also improves the output torque density and reduces the magneto-motive force (MMF) requirements. To verify the proposed structure, finite element method (FEM) is employed to get the characteristics of the proposed structure. Meanwhile, a conventional 12/8 DSBSRM is also analyzed for comparison. Finally, the validity of the proposed structure is verified by the analyzing results.