An indicator based on Wavelet and PCA to study the relationship between saline contamination and partial discharge activity in ceramic insulators

In this study, we present an indicator that establishes a relationship between environmental contamination and partial discharge activity in ceramic insulators. To develop this indicator, a method based on the use of a fog chamber was developed in which the insulators were contaminated with a degree of salinity that allowed them to exhibit high flashover activity. Simultaneously, partial discharge activity was measured and processed using Wavelet Transform and Principal Component Analysis. For each partial discharge pulse, a representative value was obtained that indicates its relationship with contamination. These results reveal the evolution of the discharges, showing the flashovers as the salinity of the insulator increases, even several minutes after the application of the saline solution. In some cases, the use of the solution was found to reduce partial discharge activity and mitigate flashovers. In this case, it has a washing effect on the salt adhering to the surface. This indicator can serve as the starting point for the creation of devices that can be placed near the insulators in the distribution lines for long periods to alert when a flashover might occur based on the evolution of the partial discharge activity.