Influence of contaminated location on streamer discharge

Pollution flashover along the insulator is a common accident in power systems with severe impacts. Researchers have conducted many studies on the external characteristics of pollution flashover along the insulator. Still, there are few studies on the physical phenomenon of streamer discharge that may disclose the mechanism of pollution flashover. In the paper, the stable propagation fields, light intensities, paths, and velocities along the clean and the contaminated dielectric surface were measured using an ultraviolet camera and three photomultipliers. The original contribution was that the contaminated location of the dielectric surface had a significant influence on surface streamer discharge. As the contaminated location moved away from the initial position of the streamer discharge, the stable propagation fields required for the streamer discharge decreased, and the streamer propagation velocities increased. Furthermore, the propagation paths of the streamer discharge were also affected by the contaminated location of the dielectric surface. The mechanism of the pollution flashover can refer to the research results of this paper, which is beneficial to increase the pollution flashover voltage of the insulator. Thus, the string length of the insulator can be reduced and the investment in power engineering can be reduced.