GIS绝缘子在冲击电压下沿面闪络的分析

利用计算和试验两种方法,对在SF_6气体中的绝缘子施加冲击电压下的电场及其引起的沿面闪络原因进行了剖析,指出在冲击电压作用下,增加屏蔽罩是减弱电极结构所引起的电场垂直分量的一条行之有效的途径;沿面闪络主要取决于电场分布的均匀度和绝缘子表面受周围环境导电微粒污染这两个基本因素;电极形状导致的局部场强增大,靠增加绝缘子沿面闪络距离不能明显提高沿面闪络电压。

ANALYSIS OF THE SURFACE FLASHOVER ON GIS BASIN INSULATOR UNDER LIGHTNING IMPULSE VOLTAGE

The electric field distribution under lightning impulse voltage applied on the insulator in SF6 gas as well as the cause of flashover is anatomized with the methods of both calculation and experiment. In the case of lightning impulse voltage stress, adding a shielding case is an effective way to decrease the vertical component of electric field generated by the electrode configuration. The surface flashover level depends mainly upon two essential factors--the homogeneous degree of electric field distribution and the insulator surface contaminated by the conductive particles in the ambient. For the partial field intensity increased by the particular electrode shape, it is useless adding the surface distance to increase the surface flashover level.