Vibration Suppression of Active Magnetic Bearing with Rotor Unbalance Control

For active magnetic bearing (AMB), unbalanced rotor mass which leads to rotor displacement fluctuations and winding harmonic currents, is an inevitable obstacle to achieving better vibration, noise, roughness. In this paper, the radial electromagnetic force model of active magnetic bearings is analyzed, and the relationship between harmonic current, rotor displacement fluctuations and radial vibration harmonic. Then, an imbalance compensation strategy based on second order generalized integral (SOGI) is proposed to suppress rotor displacement and harmonic current, compare the effects of rotor displacement and harmonic current on system vibration, and finally suppress the vibration caused by unbalanced mass. Experimental results verify the effectiveness of the proposed strategy.