A device that is mounted between a conductor of varying potential or between a conductor and a grounded member and that can withstand voltage and mechanical stress. Insulators come in many varieties and shapes. Although the structure and shape of different types of insulators are quite different, they are composed of two parts: insulation parts and connecting tools.
Insulator is a kind of special insulation control, which can play an important role in overhead transmission lines. In the early years, insulators were mostly used in telephone poles, and gradually developed into a high voltage wire connecting tower with a lot of disk-like insulators, which are hung at one end to increase the creepage distance. They are usually made of glass or ceramic, so they are called insulators. Insulators should not fail due to various mechanical and electrical stresses caused by changes in environmental and electrical load conditions. Otherwise, insulators will not play a significant role, which will damage the service and operating life of the whole line.
In the first few years of production and operation, glass insulators have been found to have the following advantages over porcelain insulators:
Due to the high mechanical strength of glass insulator surface, the surface is not easy to crack. The electrical strength of glass generally remains the same throughout the operation, and its aging process is much slower than that of porcelain. Therefore, glass insulators are mainly scrapped due to self-damage, which occurs within one year of operation, while the defects of porcelain insulators are only discovered after several years of operation.
The use of glass insulators can cancel the on-line periodic preventive tests carried out by the insulators during operation. This is because every damage to the tempered glass causes damage to the insulator, which is easily detected by operators when they patrol the line. When the insulator is damaged, glass fragments near the steel cap and iron foot become trapped, and the mechanical strength of the remaining part of the insulator is sufficient to prevent the string from breaking. The self-breaking rate of glass insulators is one of the important indicators to measure product quality, and also the basis to evaluate the quality of transmission project bidding and bidding.
