How do silicone rubber insulators work

In recent years, composite high-voltage silicone rubber insulator has been widely used in the transformation of two networks of Inner Mongolia Power Supply Bureau in the early stage because of its convenient installation, collision resistance, low cost, good insulation performance, corrosion resistance and pollution resistance. However, due to the process defects of silicone rubber insulator in the production process, the insulator is broken down in operation.

The silicone rubber insulator of the fuse is dissected and analyzed. All the hollow parts in the middle of the silicone rubber insulating sub column are discharged, resulting in black free carbonization. The analysis shows that it may be that the top of the silicone rubber insulator terminal is not tightly sealed and leaking rainwater. After multiple groups of tests, there is no sign of leakage, and the sealing is very good, which proves that the two conductive breakdown have nothing to do with rainwater erosion. Therefore, high-voltage technicians were organized to analyze, and it was considered that the dielectric balance in the air was destroyed after the interference of strong electric field in the insulating hollow barrel of silicone rubber insulator, resulting in discharge breakdown. This is because the manufacturer made the middle of silicone rubber column hollow in manufacturing and test projects. However, the central space is not treated as vacuum, so that the residual air is ionized for a long time under the action of strong electric field force, and a conductive film is formed on the hollow surface, that is, the ionized carbon increases with the running time and current, and then encounters strong lightning current and overvoltage, which destroys the balance, and finally leads to insulator breakdown and conduction.

From the analysis and judgment, it is concluded that although the electrical test of silicone rubber insulator is carried out before installation, the safe operation of the equipment can not be guaranteed. Because the generation of ionized carbon is formed after long-time charged operation. This also reminds the operators that in the equipment maintenance work, they must strictly implement the safety work procedures. When working on high-voltage equipment, they must perform the safety organization measures and safety technical measures before working, especially the operation procedures of power failure, power inspection and installation of grounding wire.

At the same time, it is also found that the metal oxide arresters produced by some manufacturers also have low reliability of silicone rubber insulators, which are very easy to cause insulation breakdown and damage to silicone rubber insulation. Therefore, the same measures are taken to gradually rotate the products of the same model, batch and manufacturer in the transformation process of the two networks, so as to avoid the troubleshooting problems after single-phase grounding of the line. At the same time, high-voltage equipment should be strengthened, Especially for the safety training of substation power failure, improving the safety awareness of all staff and ensuring the safety of power supply enterprises is to ensure efficiency