Dynamics Modeling And Vibration Suppression Of High-Speed Magnetically Suspended Rotor Condering First-Order Elastic Natural Vibration

In magnetically suspended rotor of control moment gyro (CMG), for the sake of raising the ratio of rotary inertia to rotor mass, the rotor is usually designed to have I-shaped-side-view construction, which weakens conjunction between disk and axis of rotor and reduces the frequency of first-order elastic natural vibration (ENV) characterized as relative bending between disk and axis. If this frequency is covered by control system bandwidth of active magnetic bearing (AMB), ENV becomes unstable. ENV can be depressed by inserting notch filter into AMB controller, and depression effects greatly depend on center frequency of notch filter, fc1. In order to select optimized fc1 by means of simulation, dynamic model of rotor and a method to evaluate introduced parameters, kk and kv were presented considering ENV mode. In whole rotational speed range this model was utilized to simulate ENV depression, and effects associated with different fc1 were discussed. Corresponding experiments were performed in the magnetic bearing-rotor system of CMG developed by Beijing University of Aeronautics and Astronautics. ENV amplitude was depressed to 0.1% compared to original, which verified ENV model and confirmed simulation results.