局部放电下SF_6分解组分检测与绝缘缺陷编码识别

Detection of Constituents From SF_6 Decomposition Under Partial Discharge and Recognition of Insulation Defect Coding

用SF6分解气体组分含量大小来识别全封闭式组合电器内的绝缘缺陷,须先建立分解气体组分与绝缘缺陷之间的关联法则。利用建立的SF6绝缘气体局部放电分解试验平不同类型绝缘缺陷产生的局部放电下,SF6的分解特性存在台,对4种典型绝缘缺陷进行了大量局部放电试验,发现在明显差异,其组分含量及变化率有特定的规律,为此提出用气体组分含量编码树识别绝缘缺陷的思路和方法,并对SOF2/SO2F2、CF4/CO2和(SOF2+SO2F2)/(CO2+CF4)3组气体组分含量比值范围进行了编码,建立了相应的比值编码树,得到了识别4种绝缘缺陷类型的编码组合,并针对组分含量编码处于交叉无法确定的情况,给出了最终确定编码依据的辅助方法。

To recognize the insulation defects inside the totally enclosed gas insulated switchgear （GIS） by the contents of the constituents from decomposed SF6 gas, it is necessary to establish an association rule between the decomposed gas composition and insulation defects beforehand. Utilizing the established platform for the partial discharge-caused decomposition experiments of SF6 gas, a lot of partial discharge experiments for four kinds of typical insulation defects were performed, and it was found that under the partial discharge caused by different insulation defects there were obvious differences among the decomposition characteristics of SF6 gas corresponding to these defects, and the component contents as well as their variation rates follow special law, for this reason a thinking and corresponding approach to recognize insulation defects by coding tree of gas composition contents were proposed. The ratio ranges of three groups of gas composition contents, i.e., SOF2/SO2F2, CF4/CO2 and （SOFz＋SO2F2）/（CO2＋CF4）, are coded, then corresponding ratio coding tree was established and the coding combination to recognize four kinds of insulation defects was attained. For the condition that the composition content coding fell into a cross area, an auxiliary method to finally confirm the basis of coding was given.