A study on the profile of HVDC insulators-mathematical modeling and design considerations

The effects of underrib configuration on the flashover voltage of contaminated HVDC (high-voltage direct-current) insulators are analyzed. Mathematical models are developed to characterize the behavior of multiple discharges sustained along a contaminated surface. The effectiveness of the insulator leakage length is investigated by predicting the discharge path between neighboring underrib tips. An empirical equation is developed to estimate the effectiveness of the creepage length of a profile segment in terms of its physical dimensions. It is confirmed that the effective leakage length as a direct influence on the critical flashover voltage. A method for application of the effectiveness of the insulator leakage length for profile design considerations has been developed. The method yields the optimum number of underribs required for a given insulating space.<
>