With the increasing transmission capacity of transmission lines and the development of EHV technology, the requirements for insulators are getting higher and higher. At present, the performance of porcelain insulators and glass insulators can not fully meet the needs of power operation and safety. In recent years, a new type of insulator-composite insulator has been developed.
Composite insulator, also known as composite insulator, consists of three parts: rod core, umbrella disc and metal end iron cap.
The mechanical strength is 1.6-2 times that of ordinary steel, and the pollution flashover resistance is 3-5 times that of porcelain. However, the radial (perpendicular to the center line) stress of composite insulators is very small. Therefore, it is forbidden to step on the insulator used for the pull rod or any form of radial load, otherwise it will lead to fracture. After several years of operation, the umbrella skirt will become hard and brittle, or it will easily cause bites from animals such as mice and cause injuries.
3. What are the advantages of composite insulators?
1, with strong pollution flashover resistance. The surface of composite insulator is hydrophobic, and water is granular on it, so it is difficult to form a conductive path. In addition, the composite insulator umbrella disc has small diameter, large creepage distance, high surface resistance and small leakage current, so it has high pollution lightning voltage.
2. High strength and light weight. Because the rod core has high tensile strength, the composite insulator can be made light. It can reduce the stress on the tower, reduce the intensity of installation and maintenance, and save a lot of money.
3. Good anti-aging performance. The composite insulator has good corrosion resistance and aging resistance, is still elastic at 70 degrees Celsius, and can work for a long time at 20 degrees Celsius.
4. Small size and light weight. Because the composite insulator is small in size and light in weight, the umbrella disc is flexible and not easy to be damaged, which brings great convenience to transportation, installation and maintenance.