In this article, the influence of polishing orientation on surface charge accumulation and flashover characteristics of the basin spacer in a downsized dc-gas insulated transmission line (GIL) are explored by experiments. Results show that the surface charge distribution of the polished spacers is different from the untreated one. Heteropolar charges can be observed in the polished area and outward expansion area under prestressing condition. The flashover voltages of all polished spacers are decreased. The radial polishing (RP) has the greatest impact on the flashover voltage, and the flashover voltage of the radially polished spacer is decreased by 11% under positive prestressing condition. The metal dust adsorptions of the spacers are also measured, which shows that the radially polished spacer is easier to absorb metal dust and the metal dust diffuses in the radial direction. SEM and energy spectrum scanning of different spacers show that there are more exposed alumina particles on the surface of the polished area. The microdischarge induced by alumina particles is the source of heteropolar charges. When the polished area of the spacers is repaired with epoxy paint, heteropolar charges disappear on the surface of the repaired spacer. It is confirmed that charge accumulation and flashover along the spacer surface are mainly affected by the change of surface morphology on the polished area.

中文翻译：

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影响GIL/GIS环氧隔板表面带电和闪络特性的抛光方向

本文通过实验探讨了抛光方向对小型直流气体绝缘输电线路（GIL）中盆隔板表面电荷积累和闪络特性的影响。结果表明，抛光后的间隔物的表面电荷分布与未处理的不同。在预应力条件下，在抛光区和向外扩张区可以观察到异极电荷。所有抛光隔离物的闪络电压都降低了。径向抛光（RP）对闪络电压的影响最大，在正预应力条件下，径向抛光隔板的闪络电压降低了11%。还测量了垫片的金属粉尘吸附量，这表明径向抛光的隔板更容易吸附金属粉尘，金属粉尘沿径向扩散。不同垫片的扫描电镜和能谱扫描表明，抛光区表面有较多的暴露在外的氧化铝颗粒。氧化铝颗粒引起的微放电是异极电荷的来源。当用环氧漆修复隔离物的抛光区域时，异极电荷在修复的隔离物表面上消失。证实了沿间隔物表面的电荷积累和闪络主要受抛光区域表面形貌变化的影响。氧化铝颗粒引起的微放电是异极电荷的来源。当用环氧漆修复隔离物的抛光区域时，异极电荷在修复的隔离物表面上消失。证实了沿间隔物表面的电荷积累和闪络主要受抛光区域表面形貌变化的影响。氧化铝颗粒引起的微放电是异极电荷的来源。当用环氧漆修复隔离物的抛光区域时，异极电荷在修复的隔离物表面上消失。证实了沿间隔物表面的电荷积累和闪络主要受抛光区域表面形貌变化的影响。