GIS内部气隙缺陷局部放电特征的试验研究

Study on Insulation Defects in GIS Partial Discharge

封闭式气体绝缘组合电器(Gas Insulated Switchgear,GIS)绝缘故障的前期表现为击穿前的局部放电,对此,构建了以PDchecke(r基于局部放电电流脉冲波形的局放检测仪)为核心的GIS局部放电检测系统,设计制作了GIS内部气隙缺陷的试验模型。使用脉冲电流法检测了不同发展阶段的局部放电信号。试验结果表明:气隙缺陷的局部放电具有电压相关性,即随着电压的升高,PRPD谱图中放电的幅值及放电相位会发生改变、最大放电量会在电压增加到30 kV时急剧增加,相邻2次放电的时间间隔会缩短。放电信号各自具有独特的特征,表现在PRPD(基于相位的局放分析)谱图、Qmax(最大放电量)等各个方面,PRPD谱图等参数的变化特征可以作为GIS局部放电发展程度划分的依据。

Operation experiences showed that intrinsic defects in GIS still caused accidents though its high reliability. As its reliability is very important, it is essential to assess the early fault state of GIS by effective methods. Early manifestation of GIS insulation fault is the partial discharge before breakdown. This thesis develops the PDchecker （based on partial discharge current pulse waveform detector PD） as the core of the typical GIS partial discharge detection system and designed the models and detected the partial discharge signals of different kinds and in different development process by using pulse current method. The experimental results indicated that of the models, each had its own special characteristics, furthermore, on the fact of waveforms, Phase Resolved Partial Discharge （PRPD）, Qmax and so on, The changing features of PRPD spectrograms may be taken as the basis to differentiate the risk of partial discharge.