In this paper we investigated SF₆ decomposition behaviour of typical insulation defects in gas-solid insulated converter transformer valve-side bushing under partial discharge (PD). Additionally, we compared the results with that of gas insulated switchgear (GIS). The results indicated that SF₆ decomposition behaviour varies with the insulation defects type. For metal protrusion defects, the proportion ranking of CO₂ and SO₂ can be related to whether the needle tip is wrapped with epoxy resin-impregnated paper (ERIP). The proportion of carbon-containing products is much higher under contamination defect than under other defects. Moreover, the proportion of carbon-containing components is higher under flashover condition than under PD condition and is accompanied by the appearance of H₂S and CS₂. However, the yield of SO₂F₂ is always low. Compared to negative DC voltages, positive DC voltages have a higher proportion of carbon-containing components, mainly in the form of more CO₂ and less SOF₂. Compared to the PD decomposition behaviour of typical insulation defects in GIS, when PD involves ERIP, the proportion of carbon-containing products, especially CO₂, is significant higher, while the proportion of sulphur containing products, especially SO₂F₂, is lower.

中文翻译：

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换流变压器气固绝缘阀侧套管典型绝缘缺陷局部放电下SF6分解行为

本文研究了局部放电（PD）下气固绝缘换流变压器阀侧套管典型绝缘缺陷的SF _{6分解行为。}此外，我们还将结果与气体绝缘开关设备 (GIS) 的结果进行了比较。结果表明，SF ₆分解行为随绝缘缺陷类型的不同而变化。_{对于金属突出缺陷，CO 2}和SO ₂的比例排序可能与针尖是否包裹有环氧树脂浸纸（ERIP）有关。污染缺陷下的含碳产品比例远高于其他缺陷下的含碳产品比例。而且，闪络条件下含碳成分比例高于局部放电条件下，并伴有H ₂ S和CS ₂的出现。_{然而，SO 2} F ₂的收率始终较低。与负直流电压相比，正直流电压的含碳成分比例较高，主要表现为较多的CO ₂和较少的SOF ₂。与GIS中典型绝缘缺陷的局部放电分解行为相比，局部放电涉及ERIP时，含碳产物尤其是CO ₂的比例明显较高，而含硫产物尤其是SO ₂ F ₂的比例较低。