Today talk about the basic classification and function of insulators.

The basic classification of insulators:

1. Insulators are usually divided into breakdown type and non-breakdown type.

2. According to the structure, it can be divided into column (pillar) insulators, suspension insulators, pin insulators, butterfly insulators, tension insulators, pollution-proof insulators and casing insulators.

3. According to the application, it is divided into line insulators and power station and electrical insulators. Among them, the breakdown type insulators used in the circuit include pin type, butterfly type, and disc type suspension type, and the non-breakdown type includes cross arm and rod suspension type. The breakdown type insulators used in power stations and electrical appliances include pin pillars, hollow pillars and sleeves, and the non-breakdown type includes rod pillars and container porcelain sleeves.

4. The insulators used in overhead lines include pin insulators, butterfly insulators, suspension insulators, porcelain crossarms, rod insulators and tension insulators.

5. Commonly used insulators are: ceramic insulators, fiberglass insulators, composite insulators, semiconductor insulators.

Insulator function:

A lot of disc-shaped insulators are hung on one end of the high-voltage wire connecting tower, which is to increase the creepage distance, usually made of glass or ceramics, called insulators.

In order to prevent dust and other pollution from adhering to the surface of the insulator, the formation of a path is broken down by the voltage across the insulator, that is, creepage. Therefore, increase the surface distance, that is, the creepage distance, and the distance of discharge along the insulating surface, that is, the leakage distance is called the creepage distance. Climbing distance = Surface distance/Maximum voltage of the system. According to the degree of pollution, the creeping distance is generally 31 mm/kV in heavily polluted areas.

A zero-value insulator refers to an insulator whose potential distribution at both ends of the insulator is close to zero or equal to zero during operation.

The influence of zero-value or low-value insulators: The insulation of the line wires depends on the insulator string. Due to manufacturing defects or external effects, the insulation performance of the insulator will continue to deteriorate. When the insulation resistance is reduced or zero, it is called a low-value or zero-value insulator. We have tested the lines, 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 our company's lines. The insulator is smooth, which can reduce the capacitive reactance between the wires to reduce the loss of current.