Control Design of Sensorless Magnetic Bearings for Rigid Rotor

A model of axially-symmetric lateral motion of rigid rotor supported by two radial sensorless magnetic bearings was reduced to the modal model with complex variables. Next, this model was divided into two subsystems connected with two lateral modes: translation and rotation. The controller and observer was designed independently for each mode. This approach allows to express analytically the controller and observer gains in fimction of values of desired closed-loop poles and of plant model parameters. It was appeared that gyroscopic effects influences the controller and observer parameters.