Acceleration Responses Robustness of Active Magnetic Bearings-Rigid Rotor System

Abstract

The acceleration response is a significant dynamic characteristic of active magnetic bearings (AMBs)-rigid rotor system. Currently, the research mainly focuses on the steady state characteristics of AMBs-rigid rotor system, and there are few studies on the acceleration characteristics. In this paper, taking AMBs-rigid rotor system as the object, the acceleration characteristics caused by different imbalance mass under PID controller and H∞ robust controller were studied. Firstly, the dynamic equation of AMBs-rigid rotor system in the process of accelerating motion was established. Then, the design principle of PID controller and H∞ robust controller and the stability of closed loop system were analyzed. Meanwhile, the influence of PID control parameters on the acceleration characteristics of AMBs-rigid rotor system was studied. Because of strong robustness of H∞ robust controller, the acceleration characteristics are not sensitive to the system parameters. Finally, simulation and experimental results verified the acceleration characteristics of AMBs-rigid rotor system under PID control and H∞ robust control. It is shown that the change of PID control parameters affects the acceleration characteristics of the rotor system, while the acceleration characteristics of the AMBs-rigid rotor system by H∞ robust control are almost not affected by the acceleration, which is quite different from the acceleration characteristics of PID control and traditional rotor system.