Experiment study on arc ablation resistance performance of epoxy with alumina fillers

GIS spacer plays an important role in the bus of the gas insulated switchgear in UHV substation. However, partial discharge and flashover may take place on the surface of the GIS spacer which may cause severe damage to the stability and safety of the whole system in long-term operation. In order to improve the arc ablation resistance performance of GIS spacer, micron alumina fillers are added to the epoxy system. In this paper, composites with different alumina contents ranging from 0 to 300% (alumina/epoxy in weight) was prepared to investigate their performance of resistance to arc ablation. Results showed that the addition of alumina has succeeded in improving the performance of their resistance to arc ablation, while the failure time increased from 90s to 220s. The curve was obtained between different filler content and the sample performance of resistance to arc ablation. Meanwhile, the thermal conductivity, glass transition temperature and thermal decomposition temperature of different alumina-epoxy system were measured. The conclusion indicates that the system with higher thermal conductivity performed better on the ability of resistance to arc ablation. This research helped to optimize the epoxy-alumina formulation system and to improve the electric properties of the GIS spacer.