Experimental Study of the Leakage Current in Coated Insulators Under Salt-Fog Conditions

The accumulation of contaminants in electrical insulators reduce their performance and may lead to failures. Estimating the degree of pollution of in-service equipment is not a trivial task as the process of contamination depends on several factors. It is necessary to monitor the insulators so that preventive measures can be taken in a timely manner. In this context, this paper aims to study how the amplitude, angular phase and total harmonic distortion (THD) of the leakage current can be used to monitor insulators and how these parameters are affected by the application of hydrophobic coatings. For this purpose, standard uncoated and coated glass insulator samples were subjected to electrical tests in a salt-fog chamber while the leakage current was monitored. The results show that the analyzed parameters provide relevant information about the insulation condition and how the application of hydrophobic coatings results in improvements in the insulator performance.