A Precession Effect Suppression Method for Active Magnetically Suspended Rotor

The attitude angular velocity measurement and output torque precision of magnetically suspended control and sensitive gyroscope (MSCSG) is seriously affected by the strong gyro effect (precession and nutation) of magnetically suspended rotor. This article addresses the two key challenges on the precession effect control of magnetically suspended rotor. The precise precession frequency of the magnetic suspension rotor was obtained by critical speed analysis and a novel parallel control method of PID and band stop filtering based on differential cross feedback is proposed. Based on the shortcomings of the existing control methods, the phase margin of the precession effect is improved by differential cross feedback. Then, the rotor precession effect is suppressed by the parallel control of PID and band-stop filter. By adjusting the cut-off frequency of the band stop filter, we can ensure stable operations over the entire speed ranges. The simulation results show that the proposed method can provide a greater phase lead and optimize the distribution of precession poles. The experimental results show that the power spectrum level of the precession pole using the method proposed is below −48.9 dB and the rotor tilt angle is less than 0.024°.