Formation and harm of the hottest pollution flasho

2022-08-26
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Formation and harm of pollution flashover, and measures to prevent pollution flashover accidents

1. The so-called pollution flashover is a flashover accident that occurs under normal operation conditions by accumulating polluted substances with conductive properties on the surface of road insulators and greatly reducing the insulation level of insulators after being wet in wet weather

the requirements for the surface finish of the sample are high

the polluted substances on the insulator surface are generally divided into two categories:

(1) the fine dust floating in the naturally polluted air, the salt fog brought by the sea breeze (forming salt frost on the insulator surface) and bird droppings, etc

(2) industrial pollution smoke and exhaust gas from thermal power plants, chemical plants, glass plants, cement plants, metallurgical plants and steam locomotives

the natural pollutants on the insulator surface for formal experiments are easy to be washed away by rain, while the industrial pollutants are attached to the insulator surface to form a film, which is not easy to be washed away by rain. When the air humidity is very high, it can conduct electricity and greatly increase the leakage current. If it is a wooden pole, the leakage current can make the wooden pole and wooden cross arm burn; If it is an iron tower, the insulation may be damaged due to serious flashover, resulting in power failure. In addition, partial discharge will occur on the surface of line insulator in some polluted areas in bad weather, which will interfere with radio broadcasting and communication

2. In order to prevent pollution flashover accidents of overhead line insulators, the following measures should be taken generally:

(1) regularly clean the insulators. Before the season of frequent pollution flashover accidents comes, insulators must be generally cleaned once a year; In heavily polluted areas, the number of cleaning should be appropriately increased

(2) increase the creepage distance and improve the insulation level. Such as increasing the number of insulator pieces in polluted areas, or using dust-proof insulators. The operation experience shows that the anti pollution effect is better when dust insulators are used in severely polluted areas

(3) adopt dust-proof coating, with a global BDO output of 2.75million tons, that is, ground wax, paraffin, silicone and other materials are coated on the insulator surface to improve the anti pollution ability of the insulator

if the insulator is coated with this kind of dust-proof coating, the rain water will fall on it and form droplets to roll down the surface of the insulator, which will not wet the surface of the insulator, and will not reduce the insulation level of the insulation and cause flashover. In addition, the dust-proof coating also has the function of surrounding dirt particles to isolate them from rainwater and maintain the insulation performance of insulators

(4) strengthen patrol inspection, regularly test insulators, and timely inspect defective insulators

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