发电机气隙静偏心故障前后定子绕组电磁力的对比分析  

Comparative Analysis of Stator Winding Electromagnetic Force Before and After Static Air-gap Eccentricity Fault of Generator

作　　者：何玉灵[1] 孟庆发 仲昊[1] 蒋宏春 HE Yuling MENG Qingfa ZHONG Hao JIANG Hongchun(School of Energy Power and Mechanical Engineering, North China Electric Power University, Baoding 071003, China)

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003

出　　处：《华北电力大学学报（自然科学版）》2017年第5期74-80,共7页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51307058);河北自然科学基金资助项目(E2015502013);中央高校科研业务费专项目基金资助项目(2015ZD27)

摘　　要：以QFSN-600-2YHG型汽轮发电机在气隙静偏心故障前后的定子绕组电磁力为研究对象,通过定性理论解析和定量仿真计算分别进行对比研究,获取了定子绕组电磁力在故障前后的变化规律。首先通过推导正常运行以及气隙静偏心故障下的气隙磁密表达式,得到了故障前后定子绕组电磁力的解析表达式,然后利用有限元软件Ansoft对静偏心故障前后的电磁力进行定量仿真计算,最终得出气隙静偏心故障前后的定子绕组电磁力的力学激励特性。研究结果表明:汽轮发电机静偏心前后气隙磁密中只包含奇次谐波成分,其中以基波磁密为主;单根定子绕组电磁力均呈现出近似频率为2ω的余弦函数曲线,且部分定子绕组电磁力的峰值在静偏心故障前后出现了较大差异;定子绕组电磁力只包含直流成分和偶次谐波成分,其中以直流分量及二次谐波成分为主;所有定子绕组电磁力的瞬时值呈现出一个近似2个周期的余弦函数曲线。The stator windings of domestic QFSN-600-2 YHG turbo-generator before and after the static air-gap eccentric fault are studied. The change law of electromagnetic force of stator winding before and after fault is obtained with the comparison of qualitative theoretical analysis and quantitative simulation calculation. This paper firstly deduces the expression of air-gap magnetic flux density under normal operation and air-gap static eccentric fault. On this basis,the analytical expressions of stator winding electromagnetic force before and after the fault are gained. Then the finite element software Ansoft is used to simulate the electromagnetic force under the two situations. Finally,the mechanical excitation characteristics of stator winding electromagnetic force before and after the air-gap static eccentric fault are acquired. The results show that the air-gap magnetic density of turbo-generator only contains odd harmonic,and the fundamental magnetic density is the main component. The peak value of the electromagnetic force of all the stator windings presents a cosine function curve with an approximate frequency of 2ω. And there is a big difference between the peak value of the electromagnetic force of the stator winding before and after the static eccentricity fault. While the electromagnetic force of the stator winding only contains the DC component and the even harmonic component. The DC component and the second harmonic are the main components. The instantaneous values of the electromagnetic force of all the stator windings present a cosine curve with approximate 2 cycles.

关 键 词：汽轮发电机 气隙静偏心 定子绕组电磁力 ANSOFT 

分 类 号：TM31[电气工程—电机]