Design principles of on-line insulator test stations to be used on power distribution and transmission networks

In-service monitoring of high voltage insulators installed on the power distribution and transmission networks is recognized world wide as one of the best ways to determine their operational performance. The design principles and operating details of two low cost insulator rest stations are presented.Conference Pape

Comparison of glass cap and pin, silicone rubber and EPDM rubber insulators over a four day period at Koeberg Insulator Pollution Test Station

Three 22 kV insulators with similar creepage lengths (glass, silicone rubber and EPDM rubber, the last two having identical profiles) were energised at Koeberg Insulator Pollution Test Station. Data are presented for a humid four day period, including leakage current and weather data. The interaction of the environment and the insulators is discussed.Conference Pape

The electric field of polluted insulators

In this paper a boundary element field simulaton package was used to investigate the electric fields surrounding energised polymeric insulators. Clean and polluted insulators and the effect of dry bands were considered. The high stress regions were identified and related to field observations, including water drop corona and dry band arcing. Copyright © 2002 IEEE.Articl

The effect of thermal characteristics of power line insulators on pollution performance

Power line insulators are heated by the sun and cool down during the night. The heating and cooling characteristics depend on the insulator material. The wetting of polluted insulators depends on various factors, such as humidity, ambient temperature and the temperature of the insulator surface. In this paper this phenomenon is investigated in the laboratory and on site for insulators made of various materials.Conference Pape

The prediction of insulator leakage currents from environmental data

The leakage currents of various insulators were monitored together with environmental data at a coastal test site. In addition the daily maximum surface conductivity was measured. In this paper it is shown how, using multiple regression, the leakage current can be predicted from the measured weather and environmental parameters.Conference Pape

The electric field of poluted insulators

In this paper a boundary element field simulaton package was used to investigate the electric fields surrounding energised polymeric insulators. Clean and polluted insulators and the effect of dry bands were considered. The high stress regions were identified and related to field observations, including water drop corona and dry band arcing.Conference Pape

Leakage current on porcelain and silicone insulators under sea or light industrial pollution

The leakage current on heavily polluted silicone rubber insulators is usually smaller than on similarly polluted porcelain insulators. In this paper, results are presented that show that under light contamination, the currents on the two types of insulators can have similar values. Results are also presented from two different sites that show that under certain conditions the currents on silicone insulators can be higher than on porcelain. The phenomenon is explained, referring to the superior washability of the porcelain and moisture absorption of the pollution layer on the silicone rubber insulators during times of high humidity. © 2011 IEEE.Articl

A comparison between measured leakage current and surface conductivity during salt fog tests

This paper deals with an Insulator Pollution Monitoring Relay (IPMR), designed to measure and monitor pollution on high voltage insulators. The IPMR determines the pollution severity by measuring the surface conductivity on the test insulator. The paper reports on how the IPMR was used to measure surface conductivity on the test insulator while a salt fog test was performed on typical power line insulators. The leakage currents were measured on the test insulators and the data was captured together with the surface conductivity values. The results discuss whether the IPMR is capable of the early detection of an instantaneous pollution event. The results are also utilised to compare the relationship between measured surface conductivity and leakage current values thus predicting flashover.Conference Pape

An investigation into the measurement techniques to compile an insulator pollution severity application map for South Africa

The Insulator Pollution Severity Application Map (IPSAM) for South Africa is being developed to identify pollution severity levels throughout the country. Directional Dust Deposit Gauges (DDDG's) and Equivalent Salt Deposit Density Gauges (ESDD's) are installed at various sites to measure the aggressiveness of the environment. A Geographic Information System (GIS) map was developed to accurately determine the location of pollution monitors progressively inland from the coast in order to study the effect of distance from the sea. A weather tower is used for the installation of pollution monitors to study the effect of height above ground level.Conference Pape

An investigation into the methodology to develop an Insulator Pollution Severity Application Map for South Africa

The development of an Insulator Pollution Severity Application Map (IPSAM) for South Africa is being investigated. This paper discusses the results that were obtained from Directional Dust Deposit Gauges (DDG's) and Equivalent Salt Deposit Density gauges (ESDD's) across South Africa. An investigation into the effect of distance-from-seacoast on pollution severity levels is discussed. Correlations between DDG and ESDD and between DDG and corrosion test results are also included.Conference Pape