Time–frequency analyses of leakage current waveforms of high voltage insulators in uniform and non‐uniform polluted conditions

Dhahbi-Megriche, Nabila; Béroual, Abderrahmane

doi:10.1049/iet-smt.2015.0116

Cited by 25 publications

(9 citation statements)

References 18 publications

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“…According to the FOV and LC test results given in Tables 2 and 3, the proposed model results have been obtained under uniform and LNU types of pollution for the un-aged and aged specimens. The FOV gradient equations for unaged, 2 weeks aged, 4 weeks aged, and 6 weeks aged specimens are given in ( 8), ( 9), ( 10), and (11), respectively…”

Section: Fov Gradient Fitting Modelmentioning

confidence: 99%

Experimental-based models for predicting the flashover voltage of polluted SiR insulators using leakage current characteristics

Samakosh

Mirzaie

2020

IET Science, Measurement &Amp; Technology

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This study aims to predict the flashover voltage (FOV) of silicone rubber (SiR) insulators. Accordingly, it benefits from two methods, including an artificial neural network (ANN) model and a FOV gradient fitting model. The FOV and leakage current (LC) tests are carried out on one un-aged and three aged specimens under uniform and longitudinal non-uniform pollution circumstances. The proposed ANN model is designed based on equivalent salt deposit density (ESDD), pollution non-uniformity degree, aging time, LC first harmonic magnitude I 1 , and total harmonic distortion. Furthermore, a FOV gradient model is proposed based on ESDD, I 1 , and creepage distance. To validate the proposed models, the FOV and LC tests are conducted on two different types of SiR insulators. Then, the predicted FOV from the ANN model and calculated FOV from the voltage gradient model are obtained. The results indicate that the relative errors of the ANN model and FOV gradient fitting model are <6.4 and 7.3%, respectively.

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Section: Fov Gradient Fitting Modelmentioning

confidence: 99%

Experimental-based models for predicting the flashover voltage of polluted SiR insulators using leakage current characteristics

Samakosh

Mirzaie

2020

IET Science, Measurement &Amp; Technology

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“…Regarding this matter, it is important to note that all of these factors are a well-known phenomenon that promotes the increase in the magnitude of leakage current (LC) flow over the insulator surface. Accordingly, the assessment of outdoor insulator properties and its long-term performance has been a major area of interest in the scholarly community [12]- [16].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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.

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“…The deposited surface pollutant such as dust and chemical emission is one of the biggest threats faced by outdoor insulators. Arcing and corona activities change the insulator surface characteristics, which can lead to premature ageing of insulators [11] - [14]. In addition, the surface tracking and erosion leads to material degradation.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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In this paper, an innovative approach to assess the risk of uniform/non-uniform pollution and wet high voltage glass insulator is proposed. The assessment is based on a new index, named as R hi , which is derived from the 3 rd , 5 th and 7 th harmonics of the leakage current. Two 33 kV strings of cap and pin glass insulators having three units with different profiles are employed to evaluate the risk level, based on measured critical voltage gradient (Ec). Critical voltage stress tests are executed on the contaminated insulators under different ratios of lower to upper surface (J) and wetting rates. Furthermore, the effects of ratio of soluble deposit density (ESDD) to non-soluble deposit density (NSDD) on the flashover occurrence are analyzed. It was found that the insulator profile has significant influences on the likelihood of flashover which is estimated as 38% and 24% for type A and B insulators, respectively. From the results, it can be concluded that the proposed R hi index is able to predict the risk level of the insulator and the probability of flashover occurrence more accurately than the 5th/3rd index, which is widely published in literature. INDEX TERMS Polluted insulators, Risk assessment, leakage current harmonics, Fast Fourier Transform, glass insulator.

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Time–frequency analyses of leakage current waveforms of high voltage insulators in uniform and non‐uniform polluted conditions

Cited by 25 publications

References 18 publications

Experimental-based models for predicting the flashover voltage of polluted SiR insulators using leakage current characteristics

Experimental-based models for predicting the flashover voltage of polluted SiR insulators using leakage current characteristics

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

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

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