Frequency-Varying Suppression of Vibration for Active Magnetic Bearing Using Improved Resonant Controller

This article presents an improved resonant controller for the magnetic suspension centrifugal compressor. Compared to the conventional method using shifted phase compensation, the proposed method uses a lead–lag block aiming at promising the system stability by its phase–frequency characteristic. This characteristic can realize no parameter switching during the whole working range. The stability conditions of the proposed method are analyzed in this article, and a parameter design method is given for such an approach. In addition, the rotating speed can be used as a part of the loop gain so that the ability of suppression can be enhanced at high-frequency working range. Finally, the simulation and experimental results reveal that the proposed method guarantees the system stability at low-frequency range and shows great suppression performance at full working range.