Control of Rotor Unbalance Vibration with Magnetic Dynamic Absorber

The dynamic model of magnetic dynamic absorber-rotor system is established. The equations for the equivalent stiffness and damping of the magnetic dynamic absorber are derived on the basis of the system dynamic model and operation principle of tunable dynamic absorber. Because the equivalent stiffness can be adjusted according to excitation frequency, so the rotor vibration can be controlled with the magnetic dynamic absorber in wide frequency band. The vibration absorption performance of the magnetic dynamic absorber is analyzed by means of simulation method. The results indicate that the tunable magnetic dynamic absorber has better absorption performance when a proper controller parameter k_d is selected. And the sine excitation response and step response of magnetic dynamic absorber-rotor system are also investigated at running speed. With considering system stability, settling time, overshoot and air gap between the rotor and the magnetic dynamic absorber, the controller parameter k_d is determined, and the unbalance vibration of rotor is reduced by 90% when k_d = 0.01.