High strength disc suspension porcelain insulator
Disc suspension insulators are used for insulation and suspension of conductors in high-voltage overhead transmission and distribution lines. Generally composed of insulator strings or insulator sets, used on lines of different voltage levels. Due to the vast territory of our country and the serious environmental pollution caused by industrialization, ordinary insulators are actually rarely used, mainly pollution resistant products. The main characteristic value of disc suspension insulators is their rated mechanical (electromechanical) failure load. International and Chinese national standards stipulate nine strength levels: 70 kN, 100 kN, 160 kN, 210 kN, 300 kN, 400 kN, 530 kN, 700 kN, and 840 kN. In recent years, four strength levels of 120 kN, 180 kN, 240 kN, 420 kN, and 550 kN have been derived in China according to the requirements of power users. 700 kN and 840 kN strength grade products have not yet been produced and used in China. Generally speaking, the higher the voltage level of the line, the greater the distance between the towers, and the higher the strength level of the required insulators. In addition, composite insulators are generally used for suspension strings in China's power system, and almost all tension strings use porcelain or glass insulators. In specific situations such as large span tension, it is often required to use large-tonnage disc suspension insulators. According to incomplete statistics, approximately 300000 disc suspension insulators of 400kN and above were used in the first nine months of 2008. At present, there are many manufacturers of insulators with strength levels below 160kN in China, and the market is in a saturated state. However, high-strength disc suspension insulators with strength levels above 160kN have good development opportunities due to their high technical difficulty, high equipment requirements, fewer manufacturers, and high market demand. Therefore, in terms of porcelain insulators for transmission lines, it is important to focus on developing high-strength disc suspension porcelain insulators to meet the growth needs of China's 500kV and above main power grid construction.