GIS 盆式绝缘子表面电阻率测试方法及应用

In addition to the factors that long working time causes the aging of the material, the surface resistivity is an important parameter to characteristic ageing condition. In this paper, the measurement method of surface resistivi ty of GIS spacer is proposed, and a surface resistivity measurement is developed for the surface resistivity measure ment of the insulator’s curvature surface. The surface resistivity measurement setup uses two annular electrodes, named as guarded electrode and unguarded electrode, which are in ring-shape and are close to each other with a gap in 2 mm. The central conductor of spacer can be as the guard electrode, and they formed an electrode arrangement with three electrodes. The arc length between guarded electrode and unguarded electrode can be calculated accord ing to the design size of GIS spacer. Considering to the applied voltage and steady state current, the surface resistivity of the spacer can be calculated. According to the experimental results of new and used 126 kV GIS spacers, this meth od can be used to evaluate its insulation ageing condition.