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

We utilize a nonlinear coupled force model for a two degree-of-freedom large gap 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 exponent rotor position tracking. Simulations are provided to illustrate the performance of the controller.