Insulator is a special insulation control which can play an important role in overhead transmission lines. In the early years, insulators were mostly used for telegraph poles, and gradually developed into high-voltage wire connecting towers with many disc-shaped insulators hanging at one end to increase the creepage distance. They are usually made of glass or ceramic, and they are called insulators. Insulators should not fail due to various mechanical and electrical stresses caused by changes in the environment and electrical load conditions. Otherwise, insulators will not have significant effects and will damage the service and operating life of the whole line.
Development historical origin and general situation
Origin insulator is a special insulation control which can play an important role in overhead transmission lines.
In the early years, insulators were mostly used for telegraph poles, and gradually developed into high-voltage wire connecting towers with many disc-shaped insulators hanging at one end to increase the creepage distance. They are usually made of glass or ceramic, and they are called insulators. Insulators play two basic roles in overhead transmission lines, that is, supporting conductors and preventing current from returning to earth, which must be guaranteed.
Glass insulator product structure
Tempered glass insulators for power transmission and distribution lines Generally, the main materials of insulators are iron caps, tempered glass or ceramics and steel feet, and they are integrated with cement adhesive.
Insulator action
There are a lot of dish-shaped insulators hanging at one end of the high voltage connecting tower to increase the creepage distance. They are usually made of glass or ceramic. They are called insulators.
In order to prevent dust and other pollution from adhering to the surface of the insulator, the path formed is broken down by the voltage at both ends of the insulator, that is, creepage. Therefore, increase the surface distance, that is, creep distance, the discharge distance along the insulation surface, that is, the leakage distance is called creep distance. Climb distance = surface distance/system maximum voltage. According to the degree of pollution, heavy pollution areas generally use climb distance of 31 mm / 1000 volts.
Zero value insulator refers to an insulator whose potential distribution at both ends of the insulator is close to or equal to zero during operation.
Influence of zero value or low value insulator: the insulation of the wire is dependent on the insulator string. Due to manufacturing defects or external effects, the insulation performance of the insulator will continue to deteriorate. When the absolute resistance is reduced or zero, it is called low value or zero value insulator. We have tested the line, and the proportion of zero or low value insulators is as high as about 9%. This is the company line lightning trip rate is high another main reason. Insulators are smooth, reducing the capacitive effect between wires to reduce current loss.
