支柱瓷绝缘子上下表面不均匀积污交流闪络特性

AC Flashover Characteristics of Post Porcelain Insulators with Non-uniform Pollution on Top and Bottom Surfaces

支柱绝缘子在气象因素与伞型结构的影响下易累积形成上下表面不均匀污秽,上表面污秽通常较下表面更严重。对支柱瓷绝缘子进行了不同上下表面不均匀污染条件下的人工污秽交流闪络试验,进而讨论了上下表面不均匀污染对闪络电压的影响。研究结果表明,支柱瓷绝缘子的闪络过程与悬垂串绝缘子闪络过程较相似,且飘弧现象很明显;当SDD相同时,随着支柱瓷绝缘子上下表面不均匀度的提高,闪络电压也上升;在相同的不均匀度下,支柱瓷绝缘子的闪络电压随SDD的增加而减小,随着污秽度的增加,支柱瓷绝缘子的闪络电压下降趋缓;支柱瓷绝缘子在上下表面不均匀染污下的闪络电压计算公式可用负幂函数拟合。最后,提出了上下表面不均匀污秽下闪络电压修正方法,计算值与试验值的相对误差在±5%以内。研究结果为支柱瓷绝缘子外绝缘的绝缘配合提供了技术参考。

Under the influence of meteorological factors and umbrella structure,post insulators are easy to accumulate and form uneven pollution on the upper and lower surfaces,and the pollution on the upper surface is usually more serious than that on the lower surface.In this paper,the AC flashover tests of artificial pollution under different conditions of uneven pollution on the upper and lower surfaces of post porcelain insulators are carried out,and the influence of uneven pollution on the flashover voltage is discussed.The results show that the flashover process of post porcelain insulator is similar to that of suspension string insulator,and the floating arc phenomenon is obvious.When SDD is the same,the flashover voltage increases with the increase of the non-uniformity of the upper and lower surfaces of post porcelain insulators.Under the same non-uniformity,the flashover voltage of post porcelain insulator decreases with the increase of SDD,and the flashover voltage decreases slowly with the increase of pollution.The calculation formula of flashover voltage of Post Porcelain Insulator under uneven contamination of upper and lower surfaces can be fitted with negative power function.Finally,the correction method of flashover voltage under uneven pollution on the upper and lower surfaces is proposed.The relative error between the calculated value and the experimental value is within±5%.The research results of this paper provide a technical reference for the insulation coordination of the external insulation of post porcelain insulator.