Study On Fuzzy Sliding Mode Control Of Radial Magnetic Bearings

In recent years,the magnetic suspension system received extensive attention.the electromagnetic suspension bearing system,through the electromagnetic suspension force to achieve the suspension of the magnetic bearing rotor suspension,thus the direct friction between the bearing rotor and surrounding is avoided,it can make the rotor system to achieve high speed,and also the vibration amplitude of the bearing rotor is very small.As the magnetic bearing system has so many advantages,so the system in the field of industrial production and processing,aerospace,rail transportation has a wide range of applications.In this paper,radial bearing electromagnetic bearing as the object of study.Firstly the working principle of magnetic bearing system is introduced,the characteristics and the current domestic and international development status.The process of establishing the system model of the radial electromagnet on the magnetic bearing is analyzed.Aiming at the problem that the traditional voltage and current model are limited in the process of modeling due to the linearization of the equilibrium point in the modeling process,the electromagnetic suspension force is studied as the feedback quantity to analyze when to build the model, and compared with the traditional model..Secondly,this paper introduces the sliding mode control for the problem that the overshoot is too large and the response time is long in the traditional control system,and the existence of the system chattering is analyzed.The fuzzy sliding mode control system based on electromagnetic force feedback is designed and simulated and compared with the traditional model.Finally,the hardware and software of the single-degree-of-freedom controller of the radial magnetic bearing are designed by using the TMS320F28335 digital controller in the laboratory.The fuzzy sliding mode control algorithm based on the electromagnetic levitation force feedback is used to realize the stable suspension of the magnetic bearing The experimental results show that the overshoot is less than 10%and the adjustment time is less than 0.2s when the magnetic bearing system is loaded with 30%,and the feasibility of the control algorithm is verified.