On the Influence of Controller Parameters on the Performance of Rotating System With Magnetic Bearings

Rotating machineries, in High Temperature Gas-cooled Reactor (HTGR), are usually supported by magnetic bearings. In the paper, we provide a research on the relationship between the performance of machinery and the controller parameters. More specifically, this paper concentrates on the modified Proportion-Integral-Differential (PID) controller, which is characterized by five parameters: two poles, two zeros and the gain. The system performance is evaluated by the closed-loop poles. To perform quantitative investigation, a flexible-rotor-magnetic-bearing system model is established. Based on this model, the Bode plot and root locus method are applied to analyze the effect of controller’s parameters (locations of zeros and poles along with gain) on the closed-loop performance (stability, damping ratios of closed-loop poles). The results of this paper can offer some design criterion of such controllers and help the users of rotating machinery with magnetic bearings to understand the relationship between the performance of machinery and the controller parameters.