Influence of Retainer Bearing Misalignment on the Performance of Active Magnetic Bearing

Abstract

The retainer bearing will be misaligned for mechanical errors, which leads to the uneven air gap of AMB and affects the performance of AMB. To study this problem, the electric-magnetic force model was built first with the misalignment of retainer bearing. With this model, the influences of the misalignment on the system stiffness, damping and damping ratio of AMB were studied through theory analysis and simulation based on the PID controller with low-pass filters. The study indicates that the system stiffness and damping ratio of AMB employing PID controller will increase with the increase of retainer bearing misalignment. The results provide certain references for the system structure optimum design, system debugging and fault diagnosis and performance improvement of AMB-rotor system.