The Leakage Current Components as a Diagnostic Tool to Estimate Contamination Level on High Voltage Insulators

Abstract

The current paper presents an alternative and innovative technique to predict the severity of pollution of high voltage insulator using a higher harmonics component with up to the 7 th component of leakage current. The leakage current was measured using a current transformer and a shunt resistor. Next, laboratory tests were conducted on glass and porcelain insulators with artificial pollution under salt-fog pollution state which is further represented by three levels, namely light, medium, and high contamination. In this case, the formulation of a new severity of harmonic index refers to a ratio of the sum of 5 th and 7 th to the 3 rd harmonic component. More importantly, the new index managed to provide more accurate results when used as a diagnostic tool for the levels of pollution, compared to the ratio of the total harmonic distortion (THD) to the number of odd harmonics components (n) as the boundaries. In this case, the insulators were found to be in a clean and normal condition when the K (5+7)/3 value was greater than 3%. Contrastingly, the insulators were in an extreme condition when the K (5+7)/3 was lower than 3%. Nevertheless, there is a high probability of a flashover in glass and porcelain insulators if the K (5+7)/3 value is less than 2%. The present study shows the possibility of utilizing the value of strange harmonics up to the 7 th component of leakage current as the parameter for the monitoring of leakage current in overhead insulators in the presence of contamination. Overall, it can be concluded that the 3 rd , 5 th , and 7 th harmonics details extracted from the leakage current act as a good indicator for the level of contamination. INDEX TERMS Polluted insulators, leakage current, harmonic components, total harmonic distortion, fast fourier transform, salt fog.

A Study of Multilayer Perceptron Networks Applied to Classification of Ceramic Insulators Using Ultrasound

“…Insulators that are installed in agricultural regions, where there are unpaved streets, can have organic contaminants and dust [36]. Insulators close to coastal regions generally have higher surface conductivity due to the accumulation of saline on their surface [37]. Insulators installed near large urban centers can have artificial contaminants, from industrial and pollution caused by car traffic [38].…”

Резисторный Датчик Для Диагностики Подвесных Изоляторов ВЛЭП

“…В источнике [1] описан метод, позволяющий прогнозировать степень загрязнения изолятора по соотношению 3, 5 и 7 составляющих высших гармоник тока утечки.…”

Risk Assessment of Polluted Glass Insulator Using Leakage Current Index Under Different Operating Conditions

“…This intensification of these harmonics increases the total harmonic distortion (THD) that varies depending on pollution level [29]. Based on this observation, an index that reflects the health condition of the insulators was suggested by [30]- [32]. Further, authors in [32] used the frequency components decomposition concept to propose the fifth to third harmonics ratio (which will be subsequently the 5th/3rd index) of LC to predict flashovers occurrences.…”

“…Based on this observation, an index that reflects the health condition of the insulators was suggested by [30]- [32]. Further, authors in [32] used the frequency components decomposition concept to propose the fifth to third harmonics ratio (which will be subsequently the 5th/3rd index) of LC to predict flashovers occurrences. The reported results on silicon rubber and porcelain insulators indicated that the pollution severity is closely related to the value of this ratio.…”