AC Flashover Voltage Model for Polluted Suspension Insulators and an Experimental Investigation in Salt Fog

Abstract

In recent years, the performance of polluted suspension insulators operating in coastal foggy regions has attracted attention because of the occurrence of flashover. Surface wetting by salt fog accretion increases the surface conductivity and degrades the flashover performance of insulators. Normally, the effect of conductivity under fog condition and pre-contamination on the flashover of polluted insulators are analyzed separately. However, this does not reveal the flashover behavior in salt fog, which requires further research. This paper describes salt fog experiments with an AC test voltage conducted using polluted suspension insulators in a 110-kV power system. The electrical strength performance of sample insulators with salt fog treatments is analyzed, and the effects of salt deposit density (SDD) and the conductivity of fog water (CFW) on the flashover of three types of suspension insulators are studied. The concept of additional SDD is proposed to quantify analyze the effects of salt fog. The results show that there is less dependence on CFW at higher pollution levels than at lower pollution levels. That is, the effect of CFW on U 50 can be neglected for SDD>0.15 mg/cm 2 , whereas CFW has a strong effect on U 50 for SDD<0.15 mg/cm 2. CFW has a greater influence on the critical flashover voltage of ceramic insulators than on that of silicone rubber insulator. A model for calculating the critical flashover voltage of insulators is proposed by considering the combined effect of CFW and pre-polluting SDD.

Leakage current characteristics in estimating insulator reliability: experimental investigation and analysis

“…It should be noted that testing the insulators in actual sites differs from typical experimental test setups. Recent studies [43][44][45] show that synthetic accelerated tests are used in experimental settings to study flashover states of contaminated insulators. It should www.nature.com/scientificreports/ be highlighted that all these studies are based on the standard process for insulator tests 35 .…”

Pollution Flashover Voltage of Transmission Line Insulators: Systematic Review of Experimental Works

“…Based on Figure 13, SDD is the most influential factor in effecting insulation flashover voltage. This is based on the review of 47 papers [24][25][26][27][28][29], [31], [33], [34], [36], [37], [39], [40], [42], [43], [45], [46], [48][49][50][51], [54][55][56], [58][59][60], [63], [64], [66], [67], [69][70][71][72][73], [78 -81], [86], [89 -92], [96], [97], [99], [100], [120], [122], [126], [128], [130], [131], …”

“…where A is a constant related to the insulator profile and materials and a is the contamination characteristic index of the insulator. Dong et al [26] presented the effect of SDD on the flashover voltage of three types of insulators under various fog water conductivities. According to the results, there was a nonlinear decrease of flashover voltage with increasing SDD and fog water conductivities.…”

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

“…The insulators are present both in the distribution lines of regional scope, as well as in applications of transmission lines of national scope. Therefore, its failure may be linked to the most diverse interruption scenarios [4]. Artificial intelligence techniques can be used promisingly for assessing contaminated insulators; comparative analysis is necessary, as hybrid techniques may be superior to well-established models depending on the problem being assessed [5].…”

“…To assess the failure forecast of distribution insulators, [15] uses wavelet neuro-fuzzy system. The work presented by [4] applies the group method of data handling together with the Wavelet transform, and the results are superior to well-consolidated models such as long short-term memory and adaptive neuro-fuzzy inference system.…”