刻槽绝缘子真空表面闪络光学特性

Optical characteristic of vacuum surface flashover of grooved dielectrics

利用超高速相机Hsfc-Pro对绝缘子真空表面闪络光学特性进行了研究,重点分析了平板和刻槽结构圆盘形介质样品在指状电极下闪络通道的差异以及刻槽结构对材料绝缘强度的提升。实验结果表明:槽纹的引入改变了闪络通道的形成位置,平板结构介质样品的表面闪络一般是沿两电极中心连线发展,而刻槽结构介质样品的表面闪络则是沿介质边缘发展。这导致后者的闪络时延至少是前者的π/2倍,证明了刻槽结构可以在不增加器件尺寸的前提下有效提高介质材料的绝缘强度。

Using an ultra high speed framing camera Hsfc-Pro, the development of vacuum surface flashover of grooved die lectrics is investigated. Variations in flashover images between the plane and grooved dielectric samples are compared. Then the capability of grooved dielectrics in strengthening the insulation strength is discussed. It is found that the introduction of periodical grooves alters obviously the flashover channel. With respect to the plane samples, their flashover channel develops along a straight line across the A-K gap, while for the grooved dielectrics, their flashover channel locates at the circular edge of the sam- ples. Such a bended path increases obviously the flashover distance, therefore, the flashover time delay of grooved dielectrics is at least n/2 times that of plane ones. This certifies that grooved dielectrics can increase promisingly the insulation strength without increasing their physical dimension.