Estimation of Contamination Level of Overhead Insulators based on Surface Leakage Current employing Detrended Fluctuation Analysis

This article proposes an advanced technique for condition assessment of outdoor insulators based on its surface leakage current through employing detrended fluctuation analysis (DFA). Analysis of surface leakage current of in-service insulator can be useful for assessing its surface condition. In the proposed technique, a tracker signal has been developed based on the fundamental component of surface leakage current to extract the distortions from it which carries significant information about contamination level. DFA has then been applied on the extracted distortions of leakage current to estimate its contamination level. In order to investigate experimentally, surface leakage current of 11-kV disc insulator (contaminated at different level) has been captured at different applied voltage level. The proposed technique has been applied on the captured leakage current to estimate contamination level. Results show that employment of the proposed technique provides satisfactory outcomes regarding assessment of insulator condition, which in turn improves the reliability of power system.