Study of effect of continuous discharges due water droplets on the surface of polymeric insulators

Summary

The water droplets on insulator surface play a major role in pollution flashover and ageing of insulators because of their high permittivity and conductivity. One of the ageing mechanisms responsible for the failure of the insulators is discharges on the surface of the polymeric insulators. Under rain and fog conditions, the presence of water droplets intensifies the electric field strength on the surface of a polymeric insulator. As a result, the surface corona discharges from water droplets accelerate the ageing of the shed material of polymeric insulator. Hence, this paper presents the simulation results of electric field distribution along the surface of polymeric insulators with water droplets and the results of experiments conducted to study the effect of continuous discharges on the surface polymeric insulators. The field enhancement due to water droplets on the surface of polymeric insulator is studied by means of computational simulations. The insulator is simulated under dry as well as wet conditions. The effect of water droplets on the surface of polymeric insulator with contamination layer is studied through boundary element method using Coulomb 3D software. The salt fog and a short term ageing studies of polymeric insulators are presented along with material analysis of the insulator samples. The results show that the field enhancement due to water droplets along the surface of polymeric insulator is considerable and reaches to the extent of corona formation which accelerates ageing of insulator. The leakage current variation in salt fog test is presented along with surface morphology changes and material structure before and after the tests.

Additional informations

Authors

K.A. ARAVIND, P. M NIRGUDE, D. DEVENDRANATH

Keywords

Polymeric insulators, contamination, hydrophobicity, water droplets, ageing