Visualization of partial discharge burning voltage mechanism on contaminated surfaces

Although the flashover of line insulators and outdoor equipment owing to the pollution had been recognized as a major source of interruption of power supply since a long time. However, systematic research into the pollution flashover mechanism began only in the late 1940s. Many comprehensive mathematical models to simulate the flashover phenomenon of a polluted insulator surface have been established, and some have been supported with practical and field data. A common feature of all the mathematical models is a simplified representation of the different phases of flashover of polluted insulator. Differences lie only in accurately taking into account one or all phases of the flashover phenomenon. The dry-band formation on contaminated is surface due to leakage current drying effect, and to the increase of the electric field which gives a voltage drop on formed dry bands and this give rise to partial discharge burning voltage. These partial discharge arcs are the initial phase that may lead to a total flashover. This paper presents a new visualization of the pre-flashover phase burning discharge and propose a mathematical model which may describe the burning partial discharge mechanism phase. It also introduces the results of an experimental model simulation which is carried at the KFUPM High Voltage laboratory under AC voltages to visualize the burning discharge voltage, and its variation with different contaminated surfaces.