Improving Operational Performance of Magnetically Suspended Flywheel With PM-Biased Magnetic Bearings Using Adaptive Resonant Controller and Nonlinear Compensation Method

Permanent magnet-biased magnetic bearings (PBMBs) are widely used in flywheel energy storage systems because of their comprehensive advantage in power loss and controllability. However, there is a nonlinear relationship between magnetic force, control current, and eccentric displacement of the PBMB. When the system is required to be high performance, the nonlinear dynamics of the PBMB must be considered in a control design. Therefore, this paper proposes a novel nonlinear compensator based on the nonlinear model of the PBMB and it is applied to a magnetically suspended flywheel (MSF) with PBMBs. To implement the perfect nonlinear compensation, an adaptive resonant controller is also presented to compensate the dynamics of the current-mode amplifier. Finally, the proposed method is verified by experiments on the test rig of the MSF and can be used to improve the performance of the system.