Development of Dimensional Relation of Surface Leakage Current in Correlation with Humidity and Applied Voltage Stress for a Contaminated Overhead Insulator

Many empirical relations are proposed to estimate the surface leakage current (LC) through the experimental and simulation works. However, there are less exploration on developing the empirical equation that describe the surface LC in correlation with humidity and applied voltage stress. In this paper, an empirical relationship between the surface LC with humidity and applied voltage stress is proposed by using Dimensional Analysis (DA) technique. DA introduces a systematic approach based on Buckingham Theorem to present a complex relationship between the physical quantities into a dimensionless set of products. For validation purpose, the results obtained from the proposed mathematical model are compared to the practical data from the previous researchers. The validation shows that the analytical results are within the range of experimental results. By further analyzing the quantitative error analysis; mean absolute error (MAE) and root mean square error (RMSE), the proposed model is found to be able to be used as a predictive model to estimate the performance of surface LC at different relative humidity and applied voltage stress and contribute in reducing the testing expenses.