Research on flashover characteristics of "dry band-water band" on hydrophobic surface

Abstract

Due to its outstanding anti-flashover characteristic, composite insulator has been extensively applied in power system. A lot of research has investigated flashover characteristics of hydrophobic specimens with artificial water droplets on. However, the phenomenon is not consistent with that of the contaminated composite insulators. On the test specimens covered with water droplets, there is no obvious leakage current before the flashover and no obvious relationship between flashover voltage and the conductivity of water droplets. On the contaminated composite insulator surface, there are short continuous arcs on the insulators before critical flashover, making insulators look like a luminous lantern. Considering that under these two conditions, the proportion of water along the insulation distance is different, the flashover characteristic of band-water on hydrophobicity surface was analyzed in the present study. The influence of the water band parameter (including length, width, and conductivity) as well as the length of dry band was studied. On this basis, the arc generation and development process of the surface covered with Band-water was analyzed. The research results can deepen the understanding of flashover process on contaminated composite insulator.