Decoupling control of a bearingless switched reluctance motor with hybrid-rotor

In order to solve the coupling between torque and suspended force of the traditional bearingless switched reluctance motor (BSRM), a bearingless switched reluctance motor with hybrid-rotor (HBSRM) is proposed in this paper. The HBSRM discussed in the paper has a twelve-pole stator and an eight-pole hybrid-rotor composed of a cylindrical rotor and a salient rotor. The magnetic pulling force between cylindrical rotor and stator is used to independently levitate the shaft, and that between salient rotor and stator is used to separately rotate the rotor. So, the HBSRM not only breaks the restriction of the effective output region between torque and suspended force in the traditional BSRM, but also facilitates the decoupling algorithm design and simplifies the levitation control of this bearingless motor. Firstly, the topology, operating mechanism and mathematical model of the proposed HBSRM are introduced respectively. Then the no-load decoupling control and torque ripple of the traditional BSRM and HBSRM are compared. Moreover, the load decoupling control characteristics of HBSRM are presented and verified by simulation analysis.