The traditional 12/14 bearingless switched reluctance motor (BSRM) with hybrid stator poles cannot self-start at some specific rotor position due to the two-phase structure. The new stepped rotor type BSRM solves the problem of self-start of the motor by optimization of stator and rotor structure. Based on levitation force control scheme in the traditional BSRM, this paper studies the levitation force control scheme for the new stepped rotor type BSRM. According to the natural decoupling characteristics between levitation force and torque, the independent control scheme, including hysteresis current control method and current chopper control method, is proposed to realize the levitation force and torque control. The levitation and torque control adopts PID and PI controller, respectively, to adjust the error between each parameter and the given quantity. Finally, the correctness of the control strategy is verified by simulation results.

bearingless switched reluctance motor;levitation-force control;stepped rotor