Post insulator is a special insulation control, which can play an important role in overhead transmission line. In the early years, post insulators were mostly used for power poles, and gradually developed in the connection tower of high-voltage power lines. Many suspension insulators were hung at one end to add creepage spacing. They are usually made of silica gel or ceramics, which is called insulators. Insulators play two fundamental effects in overhead transmission lines, that is, supporting conductors and avoiding current return to earth. These two effects need to be guaranteed. Insulators should not fail due to flashover and breakdown caused by changes in environmental and electrical load conditions. Otherwise, insulators will lose effect and damage the service life and operation life of the whole line.
Many disc-shaped insulators are hung at one end of the high-voltage wire connection tower to add creepage spacing. They are usually made of glass or ceramic or rubber, which is called insulators. In order to avoid floating dust and other pollutants adhering to the insulator surface, the path is flashed and broken down by both ends of the insulator, i.e. creepage Therefore, increasing the outer surface interval, i.e. creepage distance, and discharging interval along the outer surface of insulation, i.e. leakage interval, is called creepage distance Creepage distance = outer space / higher system voltage According to the different pollution degree, the climbing distance is generally 31 mm / kV in the heavily polluted area. 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 because of manufacturing defects or external effects, such as dirty insulator surface, lightning stroke, etc. The insulation function of the insulator will deteriorate continuously. When the insulation resistance decreases or is zero, it is called low value or zero value insulator. The insulator is smooth and can reduce the capacitive reactance effect between wires to reduce the loss of current.
