Flashover improvement of polluted high voltage insulators by nonlinear nanofilled hydrophobic coating

In this paper, a model for computing the dry band arcing voltage is proposed and verified by experiments on glass specimens coated with the nanofilled material with different characteristics. Such coating is to increase the dry band arcing voltage which leads to a better flashover performance of high voltage insulators. Then, a simple technique to enhance the flashover performance of high voltage insulators is presented. The proposed technique depends on coating only the insulator metal cap and pin. Studying the effect of RTV silicone rubber for metal cap and pin coating is presented and about 200% (on average) flashover performance improvement is achieved. Enhancing the cap and pin coating with a thin layer of the nonlinear nanofilled material, the flashover performance is improved by about 235% (on average). Finally, a model based on developing Obenaus's model for computing the flashover voltage is proposed. A good agreement between experimental and model results is achieved. (C) 2016 Elsevier B.V. All rights reserved.