A method for improving the performance of line insulators against pollution flashover and leakage

Traditional porcelain and glass insulators in severe fouling conditions often occur foul flash discharge, increasingly difficult to meet the requirements of transmission line operating stability and safety, mainly due to the porcelain and glass surface free energy is very high, easy to adsorb moisture and dirt reason. In order to improve the porcelain and glass insulators in severe fouling conditions flash voltage, reduce leakage current, the following measures are usually taken.

1, the design of voltage line insulators suitable geometric structure

Such as increasing the voltage line insulators creepage distance, increase the rain-proof area, the use of aerodynamic principles to reduce the accumulation of dirt and other measures. However, the practical application proves that the anti-fouling insulators designed and manufactured by these methods are effective in a clean and relatively clean environment, but the effect is very unsatisfactory in a seriously dirty environment, and there is little room for further improvement.

2, in the voltage line insulators surface coated with low free energy of the coating

Such as coating room temperature vulcanized silicone rubber RTV to prevent the formation of water film on the insulating surface. This method is more effective when newly coated, but RTV and other coatings are vulnerable to arc, ultraviolet light and other external environment, life expectancy is generally only a few years. The workload of replacing line insulators, removing damaged coatings and recoating with new coatings is huge and impossible on some lines.

3、Paste a circle of Silicone umbrella skirt on the edge of voltage line insulators

Silicone umbrella skirt is also very effective in increasing the creepage distance, but the fragile structure of the joint between the silicone umbrella skirt and the insulator affects its life and limits its use.

In addition, the above measures are only from increasing the creepage distance, changing the geometry and choosing antifouling materials, but not from improving the electric field distribution, which is the root cause of corona and flashover. Improving the electric field distribution on the outer surface of voltage line insulators, including reducing the electric field strength value of the largest area and making the electric field direction basically parallel to the upper surface of the insulator to basically perpendicular to the upper surface, can fundamentally inhibit the occurrence and development of discharge.

The new method of improving the anti-fouling flash and anti-leakage performance of line high voltage insulator introduced in this paper is focused on this, and the high temperature vulcanized silicone rubber, an excellent anti-fouling material, is used to improve the comprehensive performance of the insulator's anti-corona, flash resistance and anti-leakage, especially in the fouling and wet state, through a reliable process.