摘要
针对机械和电磁故障引起的水轮发电机组轴系振动问题,基于单节点4自由度Euler梁,将轴向位移纳入整体结构建立了单节点5自由度机组转子-轴承系统有限元模型。利用Newmark-β和Newton-Raphson相结合方法对系统进行求解,借助轴心轨迹图分别讨论了是否考虑轴向自由度和轴向电磁力下质量偏心、静偏心对系统横向振动特性的影响。结果表明:轴向自由度的加入对系统运动轨迹形态及大小起到了积极改变作用。轴向电磁力与动、静偏心下不平衡磁拉力形成电磁激励耦联效应,二者共同作用使系统横向运动振幅明显增大。因此,在水轮发电机组轴系建模及分析过程中应充分考虑轴向自由度及相关荷载作用影响。
Aiming at the shaft vibration problem of a hydraulic generating set caused by mechanical and electromagnetic faults,based on the Euler beam model with 4 degrees of freedom at single node,the finite element model of the rotor-bearing system possessing 5 degrees of freedom at each node was established by incorporating the axial displacement into the whole system.The system was analyzed by using the combination of Newmark-βand Newton-Raphson methods.With the help of axis trajectory diagram,the effects of mass eccentricity and static eccentricity on lateral vibration characteristics with and without considering the axial degree of freedom and the axial electromagnetic force,were discussed respectively.The results show that the addition of axial degree of freedom plays a positive role in changing the shape and size of the system trajectory.Considering the coupling effect between the axial electromagnetic force and unbalanced magnetic pull caused by both dynamic and static eccentricities,the amplitude of lateral motion of the system will be obviously increased.Therefore,the effects of the axial degrees of freedom and related loads should be fully considered in the process of shaft modeling and corresponding analysis for hydraulic generating sets.
作者
张雷克
范宇宏
张金剑
马震岳
王雪妮
ZHANG Leike;FAN Yuhong;ZHANG Jinjian;MA Zhenyue;WANG Xueni(College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;School of Hydraulic Engineering,Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116023,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第14期64-69,98,共7页
Journal of Vibration and Shock
基金
国家自然科学基金(51709196)。
关键词
水轮发电机组
有限元法
轴向自由度
轴向电磁力
动、静偏心
hydraulic generating set
finite element method
axial degree of freedom
axial electromagnetic force
dynamic and static eccentricities
