2种局部放电类型下SF6分解组分检测及特性分析

为研究不同绝缘缺陷引起的局部放电下SF6气体的分解特性,探索识别不同绝缘缺陷的分解气体特征量,笔者在研制的SF6气体分解试验平台上,模拟了金属突出物和绝缘子金属污染物2种典型绝缘缺陷引起的局部放电下SF6气体的分解,检测了2种缺陷下CF4、SO2F2、SOF23种分解气体的含量随时间的变化规律,并研究了2种缺陷下SOF2/SO2F2、SO2F2/CF4、SOF2/CF43组组分含量比值的特性.结果表明,2种局部放电下SF6分解生成的主要稳定衍生物中均能检测到SOF2、SO2F2和CF4,但2种缺陷下这些组分的变化规律具有显著的差异,同时研究表明,2种绝缘缺陷下SOF2/SO2F2、SO2F2/CF4、SOF2/CF43组组分含量比值具有明显的不同,因此,可以将SF6分解气体的含量比值作为识别2种绝缘缺陷类型的特征量.

Measurement and analysis of SF6 decomposition products under two types of partial discharges

In order to recognize partial discharge by analysis of SF6 decomposition products, the decomposition characteristic of SF6 under different partial discharges should be investigated, and also the feature parameters of decomposition products should be found. The decomposition of SF6 is simulated under partial discharge generated by needle defect and contamination defect respectively on the SF6 decomposition equipment made especially for the experiment. Three kinds of byproducts namely CF4, SO2F2 and SOF2 are detected, and their concentration changes with time are also studied. After that, the characteristics of three kinds of concentration ratios namely SOF2/SO2F2, SO2F2/CF4 and SOF2/CF4 under two defects are analyzed. The results show that SOF2, SO2F2 and CF4 exist in the byproducts under both the two defects. Moreover, the increase rules of the three kinds of byproducts under two defects are obviously different. Meanwhile the results illustrate that the three contamination ratios under the two defects have a notable disparity. Therefore the concentration ratios of the decomposition products can be used as feature parameters for partial discharge recognition.