Modeling and control of novel bearingless switched reluctance motor

In order to solve problems of taking traditional mechanical bearing to bear the shaft, a novel bearingless switched reluctance motor with hybrid stator poles is proposed in this paper. The rotor needs only one bearing for rotating and constraining the axial movement. The other end can move freely in the radial direction. But it is balanced with the radial force produced by the motor. The proposed motor can generate a constant suspending force independent of rotor position only using small current excitation. And torque control can be naturally decoupled form suspending force control. In order to realize steady suspension, a model for radial force is introduced and used to design the controller. In the control scheme, simple PID method and hystersis current controllers are employed. Experimental results show the validity of proposed methods.