Non Linear Control of Active Magnetic Bearings

That paper presents a non linear control scheme for active magnetic bearings involved in magnetic suspension of high speed rotor. It is based on exact linearization techniques. After introducing the non linear model of the plant, a lower dimension model is used to present the control law design. It utilizes a fictitious model of both electromagnets involved in the production of electromagnetic force along one direction. Although this model contains non analytical relations, it is possible to derive a static state feedback that linearizes this system. Extension to the global model doesn't introduce more difficulties since the sum of relative degrees equals the dimension of the model. Simulation results show the good behaviour of the controlled system, even in case of commutation between electromagnets.