Nonlinear control of a large-gap 2-DOF magnetic bearing system based on a coupled force model

A nonlinear coupled force model is used for a large-gap 2-DOF active magnetic bearing system, to develop a nonlinear backstepping-type controller for the full-order electromechanical system. The force coupled model mandates the design of a new commutation strategy to ensure that the desired force is applied to the rotor. The controller requires measurement of the rotor position, rotor velocity, and stator current, and achieves global exponential rotor position tracking. Simulations are provided to illustrate the performance of the controller