Study On Inverse System Based Control For The Bearingless Switched Reluctance Motor

The concept of bearingless switched reluctance motor (BSRM) is proposed to solve the problem of wear and tear between the bearing and shaft of the switched reluctance motor when it is running in high speed. According to the comparability between the windings of magnetic bearing and bearingless switched reluctance motor stator, the windings, which create suspending force and torque, are laminated together on the motor stator to create the steady suspending force and torque. And the motor can be realized suspending and rotating steadily by using some control strategy to adjust timely current in the motor windings.Basing on proposing the configuration of the bearingless switched reluctance motor, this paper analyses the working principle of the permanent magnet biased radial-axial direction magnetic bearing and the bearingless switched reluctance motor in detail. The mathematic model of magnetic suspension force of permanent magnet biased radial-axial magnetic bearing is proposed. Based on virtual displacement principle and magnetic equivalent circuit method, the mathematic model in theory of radial suspending force and torque of the BSRM are derived. Bearingless switched reluctance motor has the characteristics of nonlinear and strong coupling. The BSRM radial suspending system and the axial force of the permanent magnet biased radial-axial magnetic bearing are decoupling linearized using the reverse system. Robust control method is put forward to control permanent magnet biased radial-axial magnetic bearing. In the end the simulation of the two systems is described and shows the validity of controller.