不同种类气隙偏心故障对汽轮发电机转子不平衡磁拉力的影响  

Effect of different kinds of air-gap eccentricity faults on rotor UMP of a turbo-generator

作　　者：唐贵基[1] 邓玮琪 何玉灵[1] 

机构地区：[1]华北电力大学机械工程系,河北保定071003

出　　处：《振动与冲击》2017年第15期1-8,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51307058);河北省自然科学基金(E2014502052;E2015502013);中央高校基本科研业务费专项基金重点项目(2015ZD27)

摘　　要：结合理论推导和数值仿真计算分析了径向气隙偏心对汽轮发电机转子径向不平衡磁拉力及其振动特性的影响。首先通过分析气隙静偏心、气隙动偏心以及气隙动静混合偏心情况下气隙磁场的变化,分别推导得到不同气隙偏心所引起的转子径向不平衡磁拉力表达式,并分析了转子的振动特征,然后利用电机有限元软件Ansoft Maxwell建立了实验室SDF-9型隐极故障模拟发电机的二维模型,计算得到了转子水平及竖直方向的径向不平衡磁拉力变化情况,并与理论分析和部分实验振动响应进行了对比,结果基本吻合。结果表明,气隙静偏心将产生二倍频不平衡磁拉力作用于转子上;气隙动偏心根据转子表面凹凸数量分为合外力为零及合外力不为零两种情况,当合外力不为零时,将产生一倍频不平衡磁拉力作用于转子;气隙动静混合偏心将同时产生一倍频和二倍频不平衡磁拉力作用于转子上(考虑动偏心时合外力不为零的情况)。同时随着偏心程度的增大,不平衡磁拉力也随之增大。; Here, theoretical derivation and numerical simulation were used to analyze the effects of radial air-gap eccentricity on unbalanced magnetic pull （UMP） of a turbo-generator ^ s rotor and the rotor vibration characteristics. Firstly, the variation laws of air-gap magnetic field under static air-gap eccentricity, dynamic one and mixed one were analyzed. Then the rotor UMP formulas due to different air-gap eccentricity faults were deduced and the rotor vibration characteristics were analyzed. Finally, the SDF-9 type non-salient pole synchronous generator model was built with the software Ansoft Maxwell to calculate the detailed UMP data for comparing with those of theoretical analysis and parts of tests. All results of theoretical analysis, numerical simulation and tests agreed well with each other. It was shown that the static air-gap eccentricity causes a rotor UMP with a frequency of 2/ （ / is the rotor rotating frequency） ; however, there are two cases including the resultant force of zero and not zero for the dynamic air-gap eccentricity, during the latter the rotor UMP with a frequency of f is caused; in the case of mixed air-gap eccentricity, the rotor UMPs with frequencies off and 2f ,respectively are caused during the resultant force of not zero; with increase in the air-gap eccentricity, the rotor UMP increases.

关 键 词：汽轮发电机 气隙偏心 不平衡磁拉力 振动特性 

分 类 号：TM31[电气工程—电机] O323[理学—一般力学与力学基础]