抽水蓄能发电机励磁绕组匝间短路的环流特性分析  

Analysis of the Circulating Current Characteristics of Inter-turn Short Circuits in the Excitation Winding of a Pumped Storage Generator

作　　者：苟小军[1] 张玮[1] 李永刚[2] 齐鹏 张云利 王华 GOU Xiaojun;ZHANG Wei;LI Yonggang;QI Peng;ZHANG Yunli;WANG Hua(Liujiaxia Hydropower Plant,Gansu Electric Power Company of State Grid Corporation of China,Yongjing 731600,China;School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]国家电网甘肃省电力公司刘家峡水电厂,甘肃永靖731600 [2]华北电力大学电气与电子工程学院,河北保定071003

出　　处：《大电机技术》2023年第4期28-34,共7页Large Electric Machine and Hydraulic Turbine

摘　　要：针对抽水蓄能发电机励磁绕组匝间短路早期故障特征易被掩盖的问题,本文对其电枢绕组同相支路环流特性进行分析。首先,根据抽水蓄能发电机运行过程,推导了励磁绕组匝间短路状态下的同相多支路环流公式,得到了匝间短路故障所引起的环流特征谐波;其次,本文选择一台发电容量为334MVA的抽水蓄能发电机作为研究对象,搭建了二维有限元仿真模型,计算了不同故障程度下的气隙磁密大小,验证了所建模型的正确性;最后,根据所建有限元模型,对不同故障程度下的同相分支环流进行分析,并绘制了相应的时域图谱及频域图谱,实验结果证明了环流特征分布可有效用作励磁绕组匝间短路辨识的判据,该方法对早期微弱匝间短路故障检测具有较高的灵敏度。To address the problem that the early fault characteristics of inter-turn short circuit in the excitation winding of pumped storage generators are easily concealed,this study analyses the same phase branch loop characteristics of their armature windings.Firstly,based on the operation process of pumped storage generators,the equation for the same phase multi-branch loop current in the excitation winding inter-turn short circuit condition is derived and the characteristic harmonics of the loop current caused by an inter-turn short circuit fault are obtained.Secondly,a pumped storage generator with a generating capacity of 334MVA is selected as the object of study,and a twodimensional finite element simulation model is built to calculate the air gap magnetic density under different failure levels and to verify the correctness of the model built.Finally,according to the constructed finite element model,the same-phase branching circulating currents at different fault levels are analyzed,and the corresponding time-domain and frequency-domain plots are drawn.The experimental results prove that the characteristic distribution of the circulating currents can be effectively used as a criterion for the identification of inter-turn short circuit in the excitation winding,and that the method has a high sensitivity for the detection of early weak inter-turn short circuit fault.

关 键 词：抽水蓄能发电机 励磁绕组 匝间短路 环流特性 

分 类 号：TM312[电气工程—电机]