Design of PDC controller based on T-S fuzzy model for magnetic bearing of high-speed motors

Magnetic bearings can not only solve the bearing wear and life problems but also reduce the loss and noise of bearings. However, the strong non-linear and uncertainty of parameter of the magnetic bearings make the traditional PID controller difficult to ensure its long-term and stable operation. Based on the T-S fuzzy model, this paper presents a design method of magnetic bearing parallel-distributed compensation (PDC) controller for high speed motors. Firstly, linear local Takagi-Sugeno (T-S)-fuzzy model for magnetic bearing subsystem and nonlinear model for the overall system is deduced. Then the fuzzy state feedback nonlinear controller for the overall system is obtained via parallel-distributed compensation (PDC) approach and judging the stability of designed controller. Finally, the validity of controller design is verified by means of the field-circuit coupling analysis. The simulation results show that the proposed PDC controller has better performance than the conventional PID controller.