The composite insulator is composed of three sections: rod core, umbrella tray and metal-end cap. Each section of the composite insulator plays an important role by cooperating with each other. The composite insulator has good corrosion resistance, aging resistance, remaining resilient at 70 degrees Celsius and working for a long time at 20 degrees Celsius.
Since the composite insulator is elongated and its electric field distribution is uneven, in order to improve the electric field distribution as well as the arc ignition, a pair of equal-voltages should be configured for composite insulators above 10 kV.
Tests and operations have proved that the composite insulator has the following advantages:
1. Strong anti-pollution flashover resistance
The composite insulator has hydrophobicity on the surface so that it is not easy for water to form a conductive path in graininess. In addition, it has small umbrella tray diameter, large creepage distance, high resistance surface and a small leakage current, which makes relatively high pollution flashover voltage.
2. High intensity and lightweight
The composite insulator can be made light because of the high tensile strength of the rod core. It can reduce the load on the tower, reduce the intensity of installation and maintenance as well as save a lot of consumption.
3. Small size and lightweight
The composite insulator has a small size and lightweight while the umbrella tray has flexibility and it is not easy to be damaged so that it brings great convenience to transportation, installation and maintenance.
For the application of the composite insulator, although its price is higher than the porcelain insulator, the composite insulator would be ideal materials from the perspective of long-term comprehensive economic benefits. Also, the higher the voltage, the more significant its economic benefits can be predicted. With the increase of transmission capacity of power lines and the further improvement of voltage grade, the composite insulator will be widely used in the power system.