不同电场下硅橡胶直流沿面闪络特性实验研究

Experimental Study on DC Surface Flashover Characteristics of Silicon Rubber Under Different Electric Fields

为进一步探究聚合物绝缘材料的沿面闪络特性,搭建了沿面闪络实验平台,在不同电场下对硅橡胶(Si R)进行沿面闪络实验。通过图像处理技术及数值计算方法对沿面闪络光、电特性进行分析,探索并建立了沿面闪络光、电特性间的关联。结果表明:沿面闪络的光、电特性与电场分布有关。与稍不均匀电场相比,极不均匀电场下沿面闪络发光强度较低、放电通道分形维数较小;并且极不均匀电场下闪络电压较低,放电能量较小。沿面闪络的光、电特性存在一定关联。通常地,闪络电压、电流较大时,闪络通道的亮度较大且分布范围较广,沿面放电能量较高。因此,沿面闪络的光、电特性参数能够有效反映绝缘材料的沿面绝缘强度。

In order to explore the surface flashover characteristics of polymer insulating materials further, a surface flashover test platform was built and the flashover experiments were conducted on silicon rubber （SIR） under different electric fields. The optical and electrical characteristics of surface flashover were analyzed by image processing techniques and numerical methods, and then the relationship between these characteristics was investigated and established. The results show that the optical and electrical char- acteristics of surface flashover are related to the electric field distribution. Compared with slightly uneven electric field, the luminous intensity of flashover is lower and the fractal dimension of discharge channel is smaller than that under extremely uneven electric field. Moreover, both of the fiashover voltage and the discharge energy under extremely uneven electric field are lower than that under slightly uneven electric field. In addition, there is a certain correlation between the optical and electrical characteristics of surface flashover. Generally, when the flashover voltage and current are larger, the flashover channel is brighter and distributes more widely, and the surface discharge energy is higher. Therefore, the optical and electrical characteristics of the surface flashover can effectively reflect the surface insulation strength of insulating materials.