Method for Enhancing the Stability Margin of the Magnetic Bearing-Rotor System Based on a Novel Low Frequency Phase Shifter

A novel low frequency phase shifter (NLFPS) is proposed to address the challenges of insufficient stability margin and poor disturbance resistance in the bearing-rotor system of high-speed magnetically suspended centrifugal compressors (MSCCs). The NLFPS can be directly embedded into an existing magnetic bearing control system, enhancing system immunity by increasing the phase within the low frequency band. This approach effectively improves the stability margin of the system without significantly affecting the cutoff frequency. Comparative analysis with the traditional low frequency phase shifter (LFPS) demonstrates the superiority of t the NLFPS in suppressing low frequency disturbances. The feasibility and effectiveness of the NLFPS are validated through its application in a 15KW MSCC.