On The Stability And Control Method Of Magnetic Rotor-Bearing System

The magnetic bearing, as a kind of high-tech products, its development is the important change in the supporting fields, it has a far-reaching meaning and extensive application prospect, and its practical value is inestimable. In connection with the characteristic of non-linear magnetic rotor-bearing system, the control method and stability of magnetic rotor-bearing system is studied in this thesis.At first, the basic principle of the differential drive control system of the magnetic bearing has explained in the paper, the electric magnetic force of the system is simplified by adopting two dimensions Taylor progression, and then various kinds of simple results are analyzed. In term with PD and PID control methods, the simulation of the two control effects is compared Adopting Matlab, the result displays that the PD control method has stable state error, and that the integral item of PID control method can reduce the error stable state of the system effectively. Secondly, the broad sense flexible degree of the PID controller changing with its parameters and the frequency characteristic of the PID control system under the no inertia item are studied. And the relation between rigidity and damping of magnetic bearing system and its control parameters is gotten. By simulation the blindness of the design and debugging of the magnetic bearing control system can be overcome, and the simulation result can offer the theory consult for the design and debugging of the system. Thirdly, the stable state frequency respond characteristic of the magnetic rotor-bearingsystem is studied with the multi-scale method, and the result uncovers the resonance district, reverse-phase district of the frequency respond curve and the change of resonance district varying with its parameters. Fourthly, the space state equation of the rigidity magnetic rotor-bearing system is set up, and a study has been conducted on the stability of magnetic rotor-bearing system with the use of numerical integration and Poincare map method. The diagrams of time histories, phase map, axis orbit, frequency spectrum picture and Poincare map within some typical system parameters are created. The result indicates that the magnetic rotor-bearing system can produce chaos under certainly orbit partialness, the chaos sport is apt to bring out the rotor to lose stability, and should avoid the area so as to ensure the rotor steady operation while it is designed actually.The study result for being easier to control magnetic suspension rotor-bearing system offers a better theory consult.