Direct Vibration Force Suppression for Magnetically Suspended Motor Based on Synchronous Rotating Frame Transformation

Vibration force is critical in the normal operation of magnetic bearings. Among all vibration forces, the synchronous vibration force rising from rotor mass unbalance is the most influential factor. To effectively suppress the unbalance force for the high-speed magnetically suspended rotor, in this paper, a novel method for active magnetic bearings based on the synchronous rotating frame (SRF) transformation is developed. First, the structure and principle of SRF transformations for the magnetic bearing system is improved. Subsequently, different from the zero current suppression, the magnetic bearing force is directly set as the input of the vibration suppression, which is zero force suppression. In order to maintain the system stability, stability analysis, which is related to the plug-in vibration suppression algorithm, is conducted. Only one parameter needs to adjust to ensure the stability of the whole closed-loop system. Compared with the conventional method of vibration force suppression, the proposed method has better performance. The simulation and experimental results on a magnetic suspended motor system demonstrate that the proposed SRF-based method can effectively suppress the synchronous vibration force.