Analysis of natural contamination components and sources of insulators on ±800 kV DC lines

In order to study the natural contaminants and sources of ±800 kV DC line insulators, a natural pollution monitoring platform was set up to collect the natural contamination and measure its chemical composition. In this paper, enrichment factor analysis method is used to analyze the surface soluble and insoluble components and sources of insulators, and to compare the difference in contamination between the upper surface and the lower surface of insulators. The results show that the metal cations in the surface contamination of insulators are mainly caused by man-made pollution, and the insoluble components on the surface of insulators mainly come from natural pollution, and the lower surface of insulators are more seriously polluted by humans. In addition, the influence of the height on the surface contamination of the insulator is also studied. It is found that both the equivalent salt deposit density (ESDD) and non-separated deposit density (NSDD) of the de-energized insulator on the tower decrease with the increase of the height, but then decrease slowly. Insulators on high voltage lines are less polluted than insulators on low voltage lines.