Leakage Current Activity on Glass-Type Insulators of Overhead Transmission Lines in the Northeast Region of Brazil

This paper describes a study of the leakage current activity on glass-type insulators of high-voltage transmission lines over a three-month period. Three pairs of sensor systems were installed, one on a 500-kV field tower and the other two on 230-kV and 500-kV substation towers, all in the northeast region of Brazil. The locations were chosen due to their particular environment characteristics and the previous knowledge of pollution severity in these locations. The correlation of the leakage current attributes with in situ humidity records, insulator positions on the tower, and seasonality are discussed.