With the development of the power industry, the transmission capacity has increased sharply, and the voltage level has been continuously improved. 110, 220, 500, 750 and even 1000 kv have emerged and matured. The power system has higher and higher requirements for insulators, and new insulators are also emerging. Previously, porcelain insulator XP series, glass insulator LXP series, now anti-fouling porcelain insulator XWP series, tempered glass insulator FC, BC, etc., have various performances. Compared with synthetic insulators, the composite insulators stand out because of their light weight, high mechanical strength, low maintenance workload, good antifouling performance and low cost.

Synthetic insulators are called organic composite insulators, silicone rubber composite insulators.

Composite insulators can be divided into models according to model and different manufacturers: HXS series (Baoding products) FXBW series (Wenzhou Guogong, Hubei Xiangfan, Guangzhou,) FXB series (Shandong Zibo, Shanghai Hongqiao, Dalian Electromagnetic Factory) XSH series (Xiangfan, Hubei) and many more.

In our Yuncheng transmission line, the voltage level can be divided into 110kv, 220kv, 500kv.

(This article discusses the line rod suspension composite insulator)

The basic structure of the composite insulator is a metal fitting, a core rod, and a shed skirt.

The mandrel is the bearing part of the mechanical load of the composite insulator, and at the same time is the main part of the inner insulation. The core rod material of the composite insulator is composed of resin-reinforced glass fiber.

The shed skirt is the outer insulating part of the composite insulator. Its function is to make the composite insulator have sufficient outer insulation performance against moisture flashing and pollution flashing, and protect the mandrel from external environment. Generally, the shed skirt has excellent resistance. Scatter flash, resistance to tracking and erosion, resistance to high and low temperatures and atmospheric aging. The excellent resistance to flashover of composite insulators is provided by the shed skirt, which is easily damaged on the outer layer of the mandrel, so the shed skirt is also the focus of our protection and research.

The mandrel and the sheath are joined together by an intermediate bonding layer, which becomes a weak point of the internal insulation if the bonding is not good.

A metal fitting is a mechanical load connecting member of a composite insulator that is assembled with a mandrel to form a joint of a composite insulator to transmit a mechanical load.