Source strength impact analysis on polymer insulator flashover under contaminated conditions and a comparison with porcelain

A mathematical model that considers the source-insulator interaction is presented for modeling flashover of polymer and porcelain insulators under contaminated conditions. The model is shown to be capable of handling polymer insulators with varying degrees of surface wettability or hydrophobicity. While a powerful source such as a practical power system causes insulator flashover performance to be lower than what can be expected from standard laboratory test, the relative reduction is more significant for porcelain than for polymer insulators. Line post and suspension insulators up to 500 kV have been considered for this study.