Classifying insulator conditions of room temperature vulcanized coated glass insulators under different coating damage modes

•Different RTV coating damage modes on glass insulators were investigated.•Flashover voltage and leakage current of RTV coating damages were evaluated.•Leakage current indicators of harmonic index and crest factor were determined.•Support vector machine model was used to predict and classify insulator conditions.•The developed model provided accurate prediction of the insulator state. The damage of the room temperature vulcanized (RTV) coating on the surface of polluted glass insulators under axial and circumferential directions has a significant influence on the insulator's leakage current and flashover voltage. To date, many investigations have been conducted on the performance of polluted glass insulators under longitudinal, ring-shaped, and fan-shaped coating damage modes. The purpose of this research was to investigate and classify the insulator conditions of RTV coated glass insulators under different coating damage modes using flashover voltage magnitude and leakage current characteristics. The harmonic component index of leakage current used to determine the health status (H) of insulators, and the crest factor (CF) of leakage current, were experimentally extracted and utilized in the classification. The support vector machine (SVM) model with various functions was designed to predict the deterioration configuration of RTV coatings on polluted glass insulators. The results indicate that the flashover voltage and leakage current of polluted glass insulators are significantly affected by different coating damage modes. Specifically, the insulator with the fan-shaped RTV coating damage experiences the most vulnerable pollution effect compared to the undamaged coating, with a 48% drop in the flashover voltage and a 125% increase in the leakage current under heavy pollution. Subsequently, the proposed SVM model demonstrates strong capabilities for predicting the flashover voltage and leakage current and classifying the pollution severity of the RTV coating damage based on the extracted indicators.