恒压下GIS固体绝缘界面气隙缺陷放电严重程度评估  

Severity Assessment of Air Gap Defect Discharge at GIS Solid Insulation Interface Under Constant Voltage

作　　者：唐志国[1] 李阳 TANG Zhiguo;LI Yang(Beijing Key Laboratory of High Voltage&EMC,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206

出　　处：《高压电器》2024年第2期62-68,77,共8页High Voltage Apparatus

基　　金：国网宁夏省科技项目(局放类状态检测装置的可靠性与有效性评估技术研究与应用)。

摘　　要：为了研究GIS绝缘子界面气隙缺陷的放电发展过程,文中设计了空洞气隙缺陷模型,搭建了一套GIS气隙缺陷放电长期测试平台。基于缺陷模型的击穿电压对带有缺陷的试品施加90%Ub、60%Ub、30%Ub的交流恒压,使用UHF检测系统采集放电数据直至试品击穿。提取放电次数、放电幅值、放电时间间隔分析放电状态特征,发现GIS气隙缺陷放电发展过程存在两个阶段,前期放电幅值缓慢增大,放电脉冲逐渐稀疏,放电发展较为平稳;后期放电幅值急剧减小,放电脉冲密集,放电发展剧烈,采用k⁃means聚类算法及BP神经网络建立了气隙缺陷局放发展阶段的划分规则。研究表明,放电次数、放电幅值、放电时间间隔3种统计参量呈现阶段式单调性的趋势,可以用3种统计参量前向差分绝对值作为特征参量来评估GIS气隙放电严重程度;对GIS恒压试验进行聚类分析将放电过程划分为平稳劣化阶段和加速劣化阶段,随着外施电压水平的降低,平稳劣化阶段被压缩,加速劣化阶段占比升高。For studying the discharge development process of air gap defects at the interface of GIS insulators,a void air gap defect model is designed in this paper,and a long⁃term test platform for GIS air gap defect discharge is set up.Based on the breakdown voltage of the defect model,the AC constant voltages of 90%Ub,60%Ub,and 30%Ub are ap⁃plied to the test sample with defects,and the UHF detection system is used to collect the discharge data until break⁃down of the sample.The discharge state characteristics are analyzed by extracting the discharge times,amplitude and time interval,finding that there are two stages in the discharge development process of air gap defects of GIS.In the former stage,the discharge amplitude increases gradually,the discharge pulse is gradually sparse and the the discharge development is gradually stable.While,in the latter stage,the discharge amplitude decreases sharply,the discharge pulse is dense and the discharge development is drastic.The k⁃means clustering algorithm and BP neural network are used to set up the division rule of the partial discharge development stage of the air gap defect.The re⁃search shows that such three characteristic parameters as discharge times,amplitude and time interval show a trend of staged monotonicity.The absolute value of the forward difference of the three characteristic parameters can be used to assess the severity of GIS air⁃gap discharge of GIS.The cluster analysis of the GIS constant voltage test is per⁃formed to divide the discharge process into a stable deterioration stage and an accelerated deterioration stage.With the decrease of the applied voltage level,the stable deterioration stage is compressed and the proportion of the accel⁃erated deterioration stage is increased.

关 键 词：GIS绝缘子 气隙放电 恒压法 状态划分 评估 

分 类 号：TM855[电气工程—高电压与绝缘技术]