Robust Control of Rigid Rotor Active Magnetic Bearing System Based on Signal Compensation

Active magnetic bearings (AMBs) use the controlled magnetic force to achieve frictionless relative motion between the stator and the rotor. In the case of a large operating speed range, the gyroscopic effect, the unbalance force, the unmodeled dynamics and dis- turbances in the rotor-AMBs system has become a non-negligible factor that may in uence the stability and the dynamic behavior of the system. To avoid this problem, robust control methods based on signal compensation are applied to design the controllers of the rotor-AMBs system in this paper. Firstly, the rigid rotor-AMBs system is described with lumped uncertainties under sensor general coordinates system. On the basis of the model, the control system is designed. The control system contains nominal controllers and compensators. The target of the nominal controller is to stabilize the nominal part of the system. The robust compensator aims to generate the compensation signal to suppress the lumped uncertainties equivalent disturbance robustly. According to the design, we have done laboratory experiments on an AMB-supported industrial permanent magnet synchronous motor (PMSM). The results show that the design method based on signal compensation has good performance.