Adaptive control of active magnetic bearings under unknown static load change and unbalance

In this paper, a voltage level adaptive controller for a single axis of the active magnetic bearing (AMB) system is designed using an integrator backstepping technique to deal with unknown sudden static load change and unbalance. The unbalanced rotor is controlled to rotate about its geometric axis. The proposed adaptive control guarantees zero steady state error of the rotor position in presence of static load change and unbalance. The estimated parameters converge to the true values. Simulation results show satisfactory performance.