Characteristic Analysis of a New Double Stator Bearingless Switched Reluctance Motor

In order to improve the performance of bearingless switched reluctance motor (BSRM), this paper proposes a new double stator bearingless switched reluctance motors (DSBSRM). The new DSBSRM adopts an inner and outer double stator structure, the inner and outer stators are separated by magnetic isolation frame to solve the coupling problem between torque control and suspending force control. In suspending control system, the new DSBSRM adopts the working mode of hybrid excitation, permanent magnets are used to provide a bias magnetic field, electromagnetic is used to adjust the magnitude of hybrid magnetic field, thus it has larger suspending force under the same current. Further, the torque mathematical model and the suspending force mathematical model are established, and the difference caused by rotor eccentricity in air gap reluctance and in magnetic flux leakage are considered for more accurateness in the suspending force mathematical model. The 2D simulation model of the new DSBSRM is established by using finite element simulation software, and the mathematical models of torque and suspending force are verified, then the magnetic field characteristics of the new DSBSRM is analyzed, the important parameters influence of the magnetic field characteristics is analyzed. Finally, the new DSBSRM is compared with the 16-phase BSRM, the simulation results show that the torque output of the new DSBSRM is about 100% larger than that of the 16-phase BSRM, the increase percentage of suspending force varies with the change of current, but the output of suspending force is always larger than that of the 16-phase BSRM. Therefore, with the improvement of output performance, it can better cope with various workplaces.