Stabilization of the Flexible Rotor Supported by Anisotropically Controlled Magnetic Bearings

Electromagnetic bearings have attractive characteristics such as cleanliness and low drag torque, and their application has been gradually increasing. In order to get wide application, however, high-speed stability should be established. There are two kinds of coupling effects ; gyroscopic moment and inductive force. They sometimes adversely affect the system stability when the rotor runs at high speed. In this paper, a high-speed rotor supported by an anisotropically controlled magnetic bearing is analized, and the damping property and stable region are calculated using the root locus diagram. It is found from the analysis that the anisotropic controller stabilizes the inductive coupling effect drastically. This idea is applied to the 3-mass 2-journal bearing rotor, and its capability is tested.