气隙缺陷下不同局部放电强度的SF6分解特性

为掌握SF6绝缘气体在气隙绝缘缺陷下产生不同强度局部放电引起的分解特性,作者用构建的气隙绝缘缺陷物理模型在SF6分解实验平台上,分别对不同外施电压大小下的SF6进行了96 h局部放电分解实验,采用气相色谱法对分解组分进行定量检测与分析,结果表明,SF6在局部放电下均会产生CF4、CO2、SO2F2和SOF2这4种稳定的分解组分,CF4含量最少,SO2F2含量少于SOF2。局部放电强弱对4种组分含量变化及增长率的影响有所不同,且CF4/CO2、SOF2/SO2F2和(SOF2+SO2F2)/(CO2+CF4)3组分解组分比值也与局部放电强弱有着一定的关系,可以利用CF4、SO2F2和SOF2的含量变化与增长速率以及组分比值范围作为判断局部放电强弱的特征量。

Decomposition Characteristics of SF6 Under Different Partial Discharge Strengths Caused by Defected Insulation in Air Gap

To master the decomposition characteristics of SF6 under different partial discharge(PD) strengths caused by defected insulation in air gap,by use of a constructed physical model of air gap with defected insulation the decomposition experiments of SF6 caused by PD with duration of 96 hours were performed on experimental platform for decomposition of SF6 under three different applied voltages,and the quantitative detection and analysis were implemented by gas chromatography.Experimental results show that the decomposition of SF6 under PD generates four stable decomposed constituents,i.e.,CF4,CO2,SO2F2 and SOF2,among which the content of CF4 is the least and the content of SO2F2 is less than that of SOF2.The impacts of the strengths of PD on the content variation of the four constituents and their growth rates of the four constituents are different,and the there were certain relations between the PD strength and decomposed constituent ratio of two-constituent assemblies CF4/CO2 and SOF2/SO2F2 as well as between the PD and the decomposed constituent ratio of three-constituent assemblies(SOF2+SO2F2)/(CO2+CF4).Therefore,it is possible to utilize the content variation of the four constituents and their growth rates as well as the range of decomposed constituent ratio as the characteristic quantities to judge the strength of PD.