Method And Experimental Research On Active Vibration Control For Magnetic Bearing System

Magnetic bearing is a new type of bearings based on the principle of magnetic levitation.They have advantages such as simple structure,long lifespan,no contact friction,and no need for lubricants.Therefore,they have been widely used in fields such as aviation and aerospace,mechanical manufacturing,and energy storage.However,errors in the manufacturing and assembly process,external environmental interference,and inadequate processing accuracy of magnetic components may cause vibrations in the magnetic bearing system,which affects the performance and lifespan of the mechanical system.Therefore,active vibration control technology has become one of the important directions in the research of magnetic bearing systems.This article mainly studies the active vibration control algorithm of magnetic bearing systems and is divided into the following three parts:(1)Focusing on the vibration mechanism of the magnetic bearing system,special attention is given to the influence of vibration source rotor unbalance and Sensor Runout on system vibration.By analyzing the ways in which rotor unbalance and Sensor Runout are generated and the forms of vibration,a dynamic model of the system containing the vibration source is constructed,laying the foundation for further research.(2)A modified variable step-size LMS algorithm is proposed to solve the problem of rapid step-size changes when the steady-state error approaches zero in the unbalanced vibration of the magnetic bearing system.Based on this algorithm,unbalanced current suppression algorithm and unbalanced vibration force suppression algorithm are designed,which use adaptive filters and vibration force compensation methods to eliminate the influence of current and vibration force on the system.The stability analysis and simulation experiment verification of the system are carried out.The simulation experiment results show that the method designed in this article can suppress the unbalanced current and vibration force of the magnetic bearing system and complete the unbalanced vibration suppression of the magnetic bearing system.(3)A parallel LMS algorithm is proposed to address the issue of multi-harmonic vibration in a magnetic bearing system.Both multi-harmonic current suppression and multi-harmonic vibration force suppression algorithms are designed.Multi-harmonic current suppression is achieved by controlling the coil current,and multi-harmonic vibration force suppression is achieved by introducing harmonic current suppression based on same-frequency vibration suppression.The stability of the system is analyzed,and simulation experiments are conducted to validate the proposed approach.The results of the simulation experiments show that the proposed method can effectively suppress the multi-harmonic vibration of the magnetic bearing system.Finally,the experimental platform of the magnetic bearing system is used to verify the suppression effect of the designed algorithm.The experimental results show that the algorithm designed in this article can effectively suppress unbalanced vibration and multi-harmonic vibration,and achieve the active vibration control of the magnetic bearing system.