The cause and type of high voltage insulator fouling

High voltage insulator pollution of type and generation on transmission line

1.1high voltage insulator pollution on the transmission line

During the operation of overhead transmission lines, dust and salt in the air;Particles such as industrial soot or bird droppings can accumulate on the outer surface, forming a dirty layer.The accumulation of high voltage insulators means that high voltage insulators run for a period of time.The saturation value achieved by backside contamination, that is, the dynamic equilibrium state of pollutants attached to the surface of the high-voltage insulator and dirt blown away by rain and wind.Pollution degree and shape o fhigh voltage insulators;Types and extent of environmental pollution;Climatic conditions near the line are related to other factors.During the whole pollution process, when the self-cleaning effect of rain water is applied, the pollution on the surface of the high-voltage insulator is serrated.And then it goes up.Before pollution reaches saturation, the general trend is upward until saturation is reached.

1.2 types of pollution caused by high voltage insulators on transmission lines

The surface pollution of insulators on overhead transmission lines varies from environment to environment and is very complicated.However, it can be roughly divided into two categories: one is the regional pollution caused by natural conditions, the other is natural pollution;Another is industrial pollution caused by location pollution in the process of industrial production.This is industrial pollution caused by transmission line hazards.

Natural pollution

Natural pollution is caused by pollution under natural environmental conditions: usually, it is mainly:

1) dust pollution: mainly dust and dust raised from the ground by vehicles.The composition of dust and the adhesion on the surface of high voltage insulators have a great influence on the operation of line insulators.With the increase of air pollution, a lot of fertilizers are used.The development and industrialization of pesticides have increased the content of soluble conductive materials in the soil, which may lead to the decline of insulation performance of high-voltage insulators. Generally, dust pollution on the surface of high-voltage insulators is not strong, and it is easy to clean rain water.

2) salt-alkali pollution: after blowing out dust particles with salt-alkali components, salt-alkali particles will blow down the surface of online insulator with the wind. Salinity and alkalinity will absorb water from the air.Potassium, which poses a big threat to insulation.Especially in fog;Exposure to high humidity significantly reduces the level of line insulators.

Industrial pollution

Industrial pollution is the waste gas in the process of industrial production.The resulting pollutants, smog, are released into the atmosphere.Pollutants can take the form of gas, liquid particles (such as steam), or solid particles (such as dust).Industrial dirt has a strong adhesion to the surface of high-voltage insulators, making it difficult to clean rainwater.

Usually: 1) chemical pollution: acidity emitted by chemical companies;Alkaline gas does not only corrode the surface of high voltage insulators.Moreover, its strong electrical conductivity reduces the surface voltage resistance of line insulators.A serious category of industrial pollution:

2) cement pollution: it is a kind of dust particle, a weak electrolyte of calcium salt.It is an insoluble or insoluble substance.When it encounters water, it hardens and forms a rough surface on the insulator so that the surface of the line insulator can be washed away by rain.Pollutants that are blown off or blown away by the wind settle on the surface.Cement stains have strong water absorption and adhesion.Repeated downgrades make the pollution layer thicker and harder to clean.Sometimes it is a pity to replace the high voltage insulator.

3) soot pollution: mainly coal dust, which is not completely burned in the combustion process. A small amount of coal dust is discharged into the atmosphere with smoke, and coal dust becomes the condensation center of water vapor in the atmosphere.The weight of the pollution particles increases and deposits on the surface of the high voltage insulator.The conductivity of coal dust has a strong: in addition, the combustion process of coal produced by sulfur dioxide after encountered in high water vapor into sulfuric acid smog, the line of the external insulation is very bad: 4) metal contamination: metallurgical enterprises with strong natural electrical conductivity, the metal particles emitted metal particles heavier, line insulator surface is not easy to be washed away.Is actually on the surface of the overhead transmission line insulator unclean air natural sexual impurity and industry all kinds of combination of uncleanness, and this combination product and damage degree of intensified unclean, unclean usually contain soluble conductive material and unsolvable absorbent material, the first encounter water dissolves makes high voltage insulator surface filth layer conductivity increase sharply, although the latter itself conductivity is not high but absorb moisture in the air after prompted the impurity in the conductivity of conductive material increase.Unclean adhesion after hand transmission line insulation surface. In the case of the fog, dew, drizzle, filthy layer of charged ions increase, the formation of conductive water film, reduce the insulation performance of the high voltage insulator. Make its surface leakage current increases, when the leakage current increases to a certain extent, will occur pollution flashover accident of transmission line.