Investigation on DC flashover performance of porcelain insulators in high altitude areas

In this paper, experimental studies were carried out to investigate the contamination characteristics of porcelain insulators in natural high altitude areas (1970 m). The experimental results indicate that the DC arcs have a significant effect on the flashover performance at high altitudes. The insulator profiles, suspension patterns and contamination distribution have a strong effect on the arc behaviors resulting in a big difference for the utilization ratio of leakage distance of the porcelain insulator, and this had a strong influence on the flashover voltages. In addition, the effect of non-soluble deposit density and contamination components (different kinds of salt) was also investigated for porcelain insulators. Non-soluble deposit density and contamination components also had a significant influence on the flashover voltages by changing the resistance of the contamination layer.