According to statistics, solid product formed by the reaction between SF 6 gas and metal electrodes at the connecting joint of ultra-high-voltage direct current (UHVDC) wall bushing is likely to adhere to the surface of insulating materials, which may seriously threaten the insulation of the bushing. Thus, studying the effect of the solid products on DC surface flash-over voltage is of great significance for evaluating the internal insulation of UHVDC wall bushing. The electrical parameters of the solid products were measured and compared with those of epoxy-impregnated composite insulating materials. The comparison result shows that there is a significant difference between them, which demonstrate that the solid products may have an impact on the DC flash-over voltage of epoxy-impregnated composite insulating materials. Furthermore, by means of the DC surface flash-over platform, the characteristic of the surface flash-over voltage of the epoxy-impregnated composite insulating materials with the solid products attached directly is analyzed. It is found that the decrease in the surface flash-over voltage is closely related to the type of solid product, gas pressure, distance between electrodes, way of attachment, etc.

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固体产物对直流表面闪络电压影响的研究

据统计，超高压直流（UHVDC）穿墙套管连接处SF 6 气体与金属电极反应形成的固体产物很可能粘附在绝缘材料表面，严重威胁套管的绝缘。因此，研究固体产物对直流表面闪络电压的影响对于评价特高压直流穿墙套管内绝缘具有重要意义。测量了固体产品的电气参数，并与环氧树脂浸渍复合绝缘材料的电气参数进行了比较。比较结果表明，它们之间存在显着差异，说明固体产物可能对环氧树脂浸渍复合绝缘材料的直流闪络电压产生影响。此外，借助直流表面闪络平台，分析了直接附着固体产品的环氧浸渍复合绝缘材料的表面闪络电压特性。发现表面闪络电压的降低与固体产品的种类、气体压力、电极间距、附着方式等密切相关。