Field Lag Effects on the Vibrations of Active Magnetic Bearing Levitated Rotors

The authors have developed sophisticated algorithms to predict the stability of active magnetic bearing (AME) supported rotors. The rotor is modeled with finite elements while the feedback componentscontroller, power amplifier, actuators and sensors are given state space variable representations derived from their measured or predicted transfer functions. Correlation between test and theory has consistently shown an over prediction of active damping with both laminated and solid sleeve rotors. This paper shows the improvement in correlation achieved by including eddy current Ihysteresis lag and rolloff effects in the simulation model.