Insulator is a special insulation control, which can play an important role in overhead transmission line. In the early years, insulators were mostly used for electric poles, and gradually developed in the high-voltage electric wire connection tower. Many disc-shaped insulators were hung at one end to increase the creepage distance. They are usually made of glass or ceramics, which is called insulators. The insulator shall not fail due to various electromechanical stresses caused by changes in environmental and electrical load conditions, otherwise the insulator will not play a significant role and will damage the service and operation life of the whole line.

Historical origin and overview of development

Origin insulator is a special insulation control, which can play an important role in overhead transmission line.

In the early years, insulators were mostly used for electric poles, and gradually developed in the high-voltage electric wire connection tower. Many disc-shaped insulators were hung at one end to increase the creepage distance. They are usually made of glass or ceramics, which is called insulators. Insulator plays two basic roles in overhead transmission line, that is, supporting conductor and preventing current from returning to ground, which must be guaranteed.

Product structure of glass insulator

Toughened glass insulators for transmission and distribution lines. Generally, the main materials of insulators are iron cap, toughened glass or ceramics and steel feet, which are bonded with cement.

Insulator function

Many disc-shaped insulators are hung at one end of the high-voltage wire connection tower to increase the creepage distance. They are usually made of glass or ceramics, which is called insulators.

In order to prevent floating dust and other pollutants from adhering to the insulator surface and forming a path, it is broken down by the voltage at both ends of the insulator, that is, creepage Therefore, increasing the surface distance, that is, the creepage distance, and the discharge distance along the insulating surface, that is, the leakage distance, is called the creepage distance Creepage distance = surface distance / system high voltage According to different pollution levels, the climbing distance is generally 31 mm / kV in heavily polluted areas.

Zero value insulator refers to the 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 line conductor depends on insulator string. Due to manufacturing defects or external effects, the insulation performance of insulator will deteriorate continuously. When the insulation resistance decreases or is zero, it is called low value or zero value insulator We have tested the line, and the proportion of zero value or low value insulators is as high as about 9% This is another main reason for the high lightning trip rate of the company's lines. The insulator is smooth, which can reduce the capacitive reactance between wires and reduce the loss of current.