Research On Control System Of Magnetic Bearing Based On Incomplete Derivative PID

Active Magnetic bearing (AMB) is a kind of suspension part that uses magnetic force to suspend the rotor. Compared with other bearings, AMB is contactless and have lower vibration, which is promising in aerospace, energy and transportation, high precision machining and other fields. Due to the demand of application, AMB is insufficient in control. With ideal circumstance, traditional PID control can lead to good performance. But when condition gets worse and complicated interferences occur, the effect of traditional PID control can’t satisfy the demands of many applications. The improved incomplete derivative PID control is proposed against such situation.Firstly, this paper introduces the characteristics of AMB and its development. The structure and operating principle of vertical machine’s axial AMB is introduced. Power amplifier and peripheral circuit of the control chip are designed. Secondly, the math model of AMB in this paper is built and several kinds of incomplete derivative PID algorithms are introduced. And then the improved discrete incomplete derivative PID and A kind of improved digital method based on it is deduced for better steady state performance and simulated with MATLAB. Otherwise, the reset algorithm is introduced and simulated for the dynamic performance. Finally, the software of the control system is developed, and experiments are conducted to verify the algorithms above.The stable suspension of rotor in axial direction is achieved. The state error is50um, the accommodation time of the step response is0.3s and the overshot is less than1%. The results show that the design is reasonable to some extent.