Nonlinear Dymamics of Active Magnetic Bearing Systems

Active magnetic bearings (ABM) play an important role in modern high speed rotating machinery. Most of the components of an AMB-system show nonlinear characteristics which must not be neglected in a correct modeling at the system`s performance limits. Unlike to common AMB-analyses, in this project an overall nonlinear model for a magnetic bearing system is established. Equilibrium states and periodic motions of the rotor are computed and the nonlinear stability and bifurcation behavior is investigated by analytical and numerical means. The results will be useful to correctly predict the dynamical limits of an AMB-rotor system in terms of rotor speed, bearing loads, feedback control gain factors, etc. This will substantially contribute to improve the performance of an AMB-rotor system and to increase the operational safety under severe conditions. As a consequence, the area of industrial application of active magnetic bearings will be expanded in the future.