Magnetically suspend flywheel rotor speed nonlinear control

In this paper, a nonlinear speed control scheme which combines nonlinear optimal controller, nonlinear disturbance observer and adaptive kalman filter is proposed for Magnetically Suspend Flywheel (MSFW). Firstly, in order to improve the dynamic and steady-stage performances of motor driving system, the state feedback exact linearization model of BUCK converter is derived, and a nonlinear optimal controller is proposed. Considering that the runout of the suspended rotor of MSFW would induce periodic disturbance to the system, a nonlinear disturbance observer is designed to suppress the sinusoidally and synchronously disturbance. While the general disturbance that exist in the system such as circuit noise can be rejected by the improved Kalman filter which adds a fading factor to prediction covariance matrix. Finally, the validity of the proposed method has been proved by simulation and experiment.