Review of models which predict the flashover voltage of polluted insulators
Pollution of insulator surface could lead to a flashover of insulators. The flashover of insulators caused by pollution generally dominates at voltages above 500 KV. Mechanism of pollution flashover is very complex as it depends on numerous factors. Over the years researchers have presented various models for better understanding of flashover phenomenon and prediction of flashover voltages. Due to the complexity of the problem researchers made various assumptions to simplify the problem. The objective of this dissertation is to review and compare various models and to evaluate their capabilities in predicting the flashover voltages of insulators. Several models have been reviewed and out of these models, those which contain sufficient information for predicting the flashover voltages have been selected. The selected models have been applied to different types of insulators and the flashover voltages are calculated. In order to compare the models the conditions e.g. resistivity, under which the models are applied to insulators are kept the same. Five types of configurations of insulator models are considered, (i) 10 x 1 cm flat plate, (ii) 10 x 10 cm flat plate, (iii) cylinder, 100 cm long and 15 cm diameter, (iv) IEEE insulator and (v) Anti-Fog insulator. The calculated flashover voltages and other results are compared with each other and with experimental results.