Studies On Control For Magnetic Bearings Of Flywheel Energy Storage Systems

the magnetic bearing system has the performance of nonlinear dynamics and open-loop unstability, so the control system for magnetic bearing is needed. The magnetic bearing's performance is highly depended on its control system. Using optimal control theory to design the controller is more important for magnetic bearing. It was great significant to study and analyze the control methods for magnetic levitation system.Based on the FESS, the magnetic bearing is introduced and the force of magnetic bearing is analyzed and decoupled. A single degree-of-freedom (1-DOF) magnetic levitation test-bed is designed. The sensor, excitation coil and power amplifier's performances of the control system are analyzed. The force is particularly analyzed and mathematic model is derived based on this 1-DOF magnetic levitation test-bed. Studies of control theories are discussed base on this mathematic model. The controllers based on traditional control method (PID) and sliding model variable structure (SMVS) control method are discussed and simulated by MATLAB software. The performances of both control method are compared. The results of simulation show that the SMVS control method has more stability and more robust than PID control method. The SMVS control method can also reach the stability faster and has more power to restrain the noise distribution than PID control method.After the theory analysis and the MATLAB simulation, a numerical controller based on the DSP chip (TMS320LF2407) is designed. The lab experiment proved the result of simulation. The controller based on SMVS method is more stability and more robust for the magnetic levitation system.