局部放电下微水对SF_6分解组分的形成及其影响规律

摘要

H2O是影响SF6在局部放电下形成最终分解组分、组分含量及其产气速率等的重要因素之一,其影响机理及规律尚不完全清楚。本文利用研制的SF6局部放电分解试验平台,对不同H2O含量下SF6气体进行了48h局部放电分解试验,利用气相色谱检测得到了不同H2O含量的SF6在PD作用下所生成的各特征组分含量,并最终得到H2O对分解特性的影响规律。研究发现：H2O含量的增加会抑制CF4的生成,CO2的生成量高于CF4,对SO2F2和SOF2的生成均有先促进后抑制的作用,且对SOF2的促进和抑制作用都强于SO2F2;当H2O含量较低时,随局部放电时间延长,SO2F2与SOF2的浓度比即（SO2F2）/（SOF2）逐渐减小,当H2O含量较高时,随局部放电时间的增加该比值逐渐增加。因此,利用SF6放电分解特征组分来诊断设备故障时必须考虑H2O的影响。%Among the influence factors of SF6 decomposition under partial(PD) discharge,H2O is the most significant one which affects its decomposed components,component concentration as well as the rate of gas generating.However,the influence regularity and the mechanism are still unclear recently.In this paper,SF6 decomposition testing apparatus is exploited and the experiment to simulate the influence of different H2O on the SF6 decomposition under PD is conducted in 48 hours.Gas chromatograph technology is used to detecting the content of the decomposed components and the influence regularity of H2O on SF6 characteristic decomposed components under PD is finally obtained.The study indicates that the increase of the H2O content will inhibit the generation of CF4 and CO2 while CO2 concentration is higher than CF4;H2O will promote both the generation of SO2F2 and SOF2 firstly and inhibit them afterwards,yet the promoting effect and inhibition effect on SOF2 is much stronger than SOF2.Besides,when H2O content is in low condition,the concentration ratio of SO2F2 and SOF2((SO2F2)/(SOF2))will gradually decrease along with the increasing time of partial discharge;when H2O is relative high,the concentration ratio will gradually increase instead.Thus,H2O must be taken into consideration while using characteristic decomposed components of SF6 to diagnose electrical equipment fault.