A Feed-Forward Compensator for Vibration Reduction Considering Magnetic Attraction Force in Bearingless Switched Reluctance Motors

In switched reluctance motors, rotor eccentricity due to mechanical errors causes large magnetic attraction force acting on rotor in radial direction. This inherent large magnetic attraction force is one of causes of vibration that have come into problems in switched reluctance motors. The proposed bearingless switched reluctance motors can actively compensate the magnetic attraction force by employing radial force for rotor shaft magnetic suspension. In this paper, a feed-forward compensator for vibration caused by the magnetic attraction force in the bearingless switched reluctance motors is proposed. It is shown in experimental results that the proposed compensator is effective for vibration reduction and stable operation. In addition, the proposed feed forward compensator is found to be also effective for radial vibration suppression in general switched reluctance motors supported by mechanical bearings.