Modeling and low power control of active magnetic bearings system

Abstract

To meet the demands of low power control of active magnetic bearing in application, the controller is designed in the cross feedback and notch filter scheme. Considering the whole system, positive displacement cross feedback and negative velocity cross feedback are adopted to provide precession damping and nutation damping for the rotor, furthermore the cross feedback controller is designed by root locus method, eigenvalues are guaranteed in the left-half plane of the root locus map, and gyroscopic effects of the rotor are restrained; the notch compensator based on coordinate transform is adopted to compensate the synchronous component in the displacements of the rotor, and the synchronous vibration is restrained. The parameters of cross feedback controller are designed from the root locus simulation, and the control methods are validated on dSPACE digital control environment. Experimental results show that the controller based on the framework of cross feedback control and notch compensator leads to a good system performance, and the control power is prominently reduced.