水轮发电机定子线棒端部绝缘内部气隙放电特性研究  

Study on the Internal Air Gap Discharge Characteristics of the Stator Rod End Insulation of Hydrogenerator

作　　者：陈科元 马山刚[1] 金福宝[1] 冷雪健 CHEN Ke-yuan;MA Shan-gang;JIN Fu-bao;LENG(College Xue-jian of Energy and Electrical Engineering,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学能源与电气工程学院,青海西宁810016

出　　处：《水电能源科学》2024年第8期155-159,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51865049);青海省科技厅基础研究计划项目(2020-ZJ-708)。

摘　　要：水轮发电机定子线棒端部绝缘层多为手工绕制而成,其所造成的内部气隙缺陷极易导致局部放电,从而劣化绝缘,降低定子线棒绝缘性能,甚至引发重大电力安全事故。为此,根据实际运行中水轮发电机定子线棒端部的绝缘结构,构建端部主绝缘内部气隙放电模型,结合气隙模型计算放电参数,并基于Simulink研究气隙缺陷放电的发展过程;同时,开展气隙缺陷模型局部放电试验,采用脉冲电流法检测放电特征参数,依据放电统计特征图谱和相关放电理论研究绝缘内部气隙放电规律。结果表明,定子线棒端部绝缘气隙内部电场变化对气隙放电影响较大;气隙空间电荷的累积效应使放电相位发生偏移;气隙放电可分为放电发展阶段、加速发展阶段及稳定发展阶段,根据各阶段的放电特性可以有效判断线棒的绝缘状况;此外,气隙缺陷大小不影响各放电发展阶段的变化趋势。研究结果为水轮发电机定子线棒端部局部放电在线监测和检修维护提供了理论依据,有利于提升发电机的绝缘性能,延长定子线棒使用年限。The insulation layer of stator rod end of hydrogenerator is mostly hand-wound,and the internal air gap fects de-are very easy to cause partial discharge,which degrades the insulation,reduces the insulation performance of the stator bar and even causes a major power safety accident.According to the insulation structure of the stator bar end of the hydrogenerator in actual operation,an internal air gap discharge model was constructed for the main insulation at the end.The discharge parameters were calculated by combining with the air gap model,and the development process of air gap fective de-discharge was studied based on Simulink.The partial discharge test of the air gap defect model was carried out.The characteristic parameters of the discharge were detected by the pulse current method,and the internal air gap charge dis-law of the insulation was investigated based on the discharge statistical characteristic patterns and the relevant charge dis-theory.The results show that the variation of the electric field inside the insulating air gap at the end of the stator bars has a large influence on the air gap discharge;The cumulative effect of the air gap space charge shifts the phase of the discharge;The air gap discharge can be divided into the discharge development stage,accelerated development stage,and stable development stage;The insulating condition of the stator bar can be effectively determined by the discharge teristics charac-of the various phases;In addition,the size of the air gap defects does not affect the change trend of the various ges sta-of the discharge development.The results of the study provide a theoretical basis for online monitoring and nance mainte-of partial discharges at the stator bar ends of hydrogenerators,which is conducive to improving the insulation formance per-of the generators and prolonging the service life of the stator bars.

关 键 词：定子线棒 气隙放电 SIMULINK仿真 放电特性 放电图谱 

分 类 号：TM312[电气工程—电机]