High strength disc suspension porcelain insulator
Disc suspension insulators are used for insulating and suspending conductors in high-voltage overhead transmission and distribution lines. Generally composed of insulator strings or insulator string sets, used on lines with 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 domestic 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 grades of 120 kN, 180 kN, 240 kN, 420 kN, and 550 kN have been derived at the request of power users in China. 700 kN and 840 kN strength grade products have not been produced and used in China. In general, the higher the line voltage level, the greater the distance between poles and towers, and the higher the strength level of the required insulators. In addition, composite insulators are currently commonly 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, in the first nine months of 2008, about 300000 disc suspension insulators of 400 kN and above were used. Currently, there are many domestic manufacturers of insulators with strength grades below 160kN, and the market is in a saturated state. However, high-strength disc suspension insulators with strength grades above 160kN have good development space due to greater technical difficulties, high equipment conditions, fewer manufacturers, and large market demand. Therefore, in the field of porcelain insulators for transmission lines, it is necessary to focus on developing high-strength disk suspension porcelain insulators to meet the growing demand for the construction of 500 kV and above main power grids in China.