Anti-pollution Flashover Coating for Ceramic and Glass High Voltage Insulators

As we all know, outdoor insulators will be polluted by industrial pollution or natural salt alkali, dust and so on. Porcelain or glass insulator string has serious creepage phenomenon in fog and rain, so that the leakage current of the insulator increases sharply and the flashover voltage of the insulator is greatly reduced, and flashover may even occur under the working voltage.

1. High-voltage insulators urgently need anti-pollution flashover coatings

If pollution flashover occurs under working voltage, it will often cause large-scale and long-term power outages and pollution flashover. Pollution flashover has become a major factor affecting the safe operation of high-voltage lines.

Due to the limitation of the line tower structure, the glass and porcelain insulator strings cannot be too long. Therefore, it is imperative to improve the pollution resistance of existing ceramic and glass high-voltage insulators, and to use anti-pollution flashover coating to reduce pollution flashover accidents.

2. Working principle of anti-pollution flashover coating

The structure of porcelain insulators is diverse and complex. At present, the main problem is to control the pollution layer. If the original hydrophilic inorganic surface of the insulator can be successfully changed to a hydrophobic low-energy surface, it will prevent the formation of a serious water film due to non-polar molecular clusters, forming a dry zone between each droplet, and as a result, leakage current could be avoided.

The use of anti-pollution flashover coatings can reduce leakage current, so that insulators will not flashover or its structural parts will not be degraded. Through this hydrophobic effect, it can also simplify the structure.

Through analyzing the inorganic surface structure of insulators, it can be known that a large number of hydrophilic groups (hydroxy-OH) are distributed on the surface of ceramic glaze after high temperature sintering. These highly active groups can make various organic and inorganic salts in the ceramics root on the surface, which will cause pollution flashover accidents. By enclosing the hydrophilic groups and linking with another hydrophobic material with extremely low surface energy and excellent weather resistance-Ruisen Anti-pollution Flashover Coating RTV-II, the hydrophilic properties of the ceramic surface can be changed into the hydrophobicity so that the surface of the insulator has excellent hydrophobicity.

3. The role of Ruisen Anti-pollution Flashover Coating RTV-II

Ruisen Anti-pollution Flashover Coating RTV-II is chemically linked with the hydroxyl -OH on the ceramic surface. Combined with the ceramic as a whole, the RTV-II will solidify on the surface of the ceramic glass to form a hard coating and water-repellent layer. It will not bury pollutants, and it will not become saturated, so there is no need to remove surface dirt. And it can remove pollutants by itself with the wind and rain.

Under natural wet weather conditions such as rain, fog, frost, dew, etc., with the increase of fogging time, the fog gradually accumulates on the surface of the ceramic insulator. Since the surface has been coated with Ruisen Anti-pollution Flashover Paint RTV-II, water vapor would become small water droplets. Good water repellency makes it difficult for water droplets to form a continuous water film on the surface of the insulator. Water can only form scattered water droplets on the surface. It is difficult for the dirty layer on the surface of the insulator to be damp uniformly at the same time.

Before the insulator reaches the saturated damp condition, the volume of the water droplets gradually increases with the increase of the water collected by the water droplets. Under the action of gravity, the larger water droplets slide off the surface and take away some of the salt at the same time, which reduces the pollution and salinity of the surface. There is no continuous water film on the surface of the insulator to form a conductive channel, and at the same time the salt is gradually lost. As a result,with the surface coated with Ruisen Anti-pollution Flashover Paint RTV-II, ceramic insulators,which is excellent hydrophobicity, have good pollution flashover resistance.