Insulator Pollution Research Articles

Watch the birdie

Electrical faults on transmission lines are an important source of power disturbances. These faults have a variety of causes, including fires, lightning, insulator pollution, animal electrocutions, and equipment failure. Important faulting mechanisms that have hitherto been largely overlooked are bird streamers. In this article, the role of bird streamers as a faulting mechanism are discussed, as well as remedies to reduce the problem. Results obtained in South Africa through the application of remedies are presented.

Investigation on Reduction Techniques of Wind Noises from High Strength Anti Pollution Insulator Strings.

Investigation on Reduction Techniques of Wind Noises from High Strength Anti Pollution Insulator Strings.

A Model for the Flashover Process on Non-Uniformly Polluted Insulators

The flashover process over polluted insulators is described by well-known analytical equations, published by various investigators, mainly Obenhaus and Alston. These procedures were used for the formulation of a mathematical model that permits determination of the parameters of the flashover under uniform or non-uniform pollution of the insulator. The calculated values were found to be in agreement with laboratory tests on artificially polluted insulators. All the experimental techniques use uniform distribution of the pollution layer on the surface of the insulator. Tests on artificially polluted insulators under non-uniform pollution are rare. On the other hand, Rizk measured the deposit of natural pollution on the surface of various insulators for a long period of time. The mathematical model of this work was applied for the calculation of the dielectric strength of the insulator under the determined non-uniform distribution. The type of insulator investigated here is similar to the ones of Rizk. The surface of the insulator is divided into finite elements, uniformly contaminated, across the creepage length. The required parameters for the calculation of the critical voltage for the flashover are the dimensions of the insulator, the arc constants, and the specified distribution of the pollution. The dependence of the critical voltage upon the distribution of the pollution layer and the total pollutant deposit on the insulator are also presented.

変電所がいし洗浄時期決定の自動化システム:複数事象中心予測に基づく汚損予測法

変電所がいし洗浄時期決定の自動化システム:複数事象中心予測に基づく汚損予測法

条件付事象中心予測法による変電所がいしの汚損予測と洗浄時期決定

条件付事象中心予測法による変電所がいしの汚損予測と洗浄時期決定

A Study of Automatic Decision Making for Washing the Polluted Insulators in Coastal Substations Based on the Prediction by Use of Pollution Model with Weather Information

Insulators in coastal substations are rapidly polluted due to the salty wind blowing from the sea. The insulator pollution causes higher leakage current and ultimately gives rise to blackouts due to flash-over. This research is aimed at developing a method of reliable automatic decision making for washing the polluted insulators in substations near coastal areas. The proposed method makes use of a model of pollution deposits which was constructed based on the actual data of pollution deposits and weather information at Karatsu substation and Nishikyushu substation. Decision is made automatically using the predicted pollution deposits, which is obtained from the pollution deposits model. Effectiveness of the proposed method is assured by applying it to the actual data.

Power line insulator pollution and power dips in natal, South Africa

Air pollution is a recognized factor in power transmission line failures in South Africa, causing insulator flashovers which lead to power dips. A number of management strategies are in operation to try to overcome the problem. A severe faulting episode which occurrence of three major contributing factors. paper. It is concluded that the episode resulted from the concurrence of three major contributing factors. These were the presence of an atmospheric circulation with high air pollution potential, the occurrence of runaway forest, veld and cane fires and a long period of below average rainfall prior to the event. The slow buildup of salt and industrial pollution during winter, the likelihood of dew formation which wetted the insulator surface making it conductive, and the rapid buildup of carbonaceous material all contributed to the faulting episode.

Design of HV transmission lines to combat insulator pollution problems in the eastern region of Saudi Arabia

In an attempt to understand the severity of prevailing pollution in eastern Saudi Arabia, two insulator research stations were erected. At these two stations, pollution buildup characteristics of different representative insulators were investigated and, depending on the length of pollution cycle, relevant design pollution levels were determined. These conditions were subsequently simulated in the high voltage laboratory at the King Fahd University of Petroleum and Minerals and the performance of representative insulator designs was evaluated. Based on these investigations, insulation design requirements for combating pollution flashover were identified.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Insulator pollution performance at high altitude: major trends

Insulator pollution performance at high altitude: major trends

Insulator Pollution Performance at High Altitude: Major Trends

A survey of the data available from the literature was conducted in order to assess major trends in insulator performance with altitude. The literature comprised tests on individual insulator strings under natural and artificial conditions along with actual live-line performance. The data covered pollution performance as well as the air-gap breakdown performance of insulators under reduced pressure conditions for AC and DC applied voltages. The major trends reported here suggest a pressure dependence (p/p/sub 0/)/sup 0.35/ for DC and (p/p/sub 0/)/sup 0.5/ for AC, of V/sub 50/ for standard polluted insulators at altitudes lower than about 4 km (p approximately 0.6 atm). These pressure dependences impose a derating of the relative performance of leakage path length or flashover voltage with altitude, namely 6%/km for AC, 5%/km for positive DC, and 4%/km for negative DC applied voltages. Dielectric breakdown, in contrast, imposes a 10.5%/km degradation of insulating air gaps with altitude. >

Variable-voltage application for insulator pollution tests

The speed and precision of salt fog contamination testing of insulators is improved using stepwise voltage application to give numerous flashovers in a single test. A similar technique for the clean fog method, which gives comparable results to conventional tests at constant voltage, is proposed. Valuable information on the performance of naturally contaminated ceramic insulators, directly comparable to that for artificial contamination, can also be obtained. With the same technique, the performance of naturally or artificially aged and contaminated nonceramic insulators can be studied and the aging process monitored as it proceeds.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A new monitor for pollution on power line insulators. Part 2: Simulated field tests

An apparatus is developed for monitoring the leakage currents drawn by an insulator chain of a power line or a busbar support in a polluted atmosphere. The apparatus monitors the insulator pollution by sensing and analysing the leakage current bursts. If these bursts are judged by the apparatus as corresponding to a potentially dangerous pollution level, the apparatus transmits an alarm signal to the service crew to allow them to clean the insulators of the line or substation in time before a sudden line outage occurs, with the entailed excessive expense, loss of power supply and annoyance to customers. Line insulator cleaning is thus carried out only when necessary, which adds to the economy of the power system operation. The apparatus design and construction were reported in Part 1 of the paper. It has undergone numerous tests with artificially polluted insulators in the high voltage laboratory. These tests are the subject of the present paper. The following Part, to be submitted, will describe field experience.

Artificial- and natural-pollution tests on outdoor 400 kV substation insulators

Pollution tests have been made on a range of 400 kV substation insulators using both natural- and artificial-pollution methods. Agreement between the results of the different test methods is good. The effects of various design parameters on insulator pollution performance have been evaluated.

Pollution of suspension-type insulators on overhead lines

Pollution of suspension-type insulators on overhead lines