Overhead power lines to increase the span, the traditional widely used ACSR. To further increase the transmission flow, people seek to develop lightweight, high strength, low sag, corrosion resistance, low line loss of the new cable. Since the 90s of last century, the United States, Japan has successfully developed carbon fiber composite material core overhead conductors, is now in engineering applications. China has imported this wire from the United States for transmission engineering. At present, Jiangsu, Beijing, Liaoning and other places have started independent research and development.
ACSR fully utilizes the electrical conductivity of aluminum and the high mechanical strength of steel, the structure of aluminum wire wrapped single or multi-strand steel wire or strand. Aluminum twisted steel core from the atmosphere of harmful gases (such as nitrogen oxides, sulfur dioxide) erosion. Steel core bear the mechanical stress, aluminum wire bear the function of conveying electric energy. As the aluminum strands in the outer wire, the skin effect principle can be seen, this wire is more efficient. The core material of the aluminum wire wind swing small amplitude, even the wire with less chance of failure, its sinking than the non-core aluminum wire nearly 50% smaller, is conducive to the safe operation of the circuit.
The manufacturing process of the carbon fiber composite material core is pultrusion forming. Carbon fiber can choose T700S (tensile strength of 4900MPa, tensile modulus of 230GPa, breaking elongation of 2.1%, density of 1.80g / cm3), the substrate can be low viscosity, good heat resistance and toughness of epoxy resin. Wuhan University of Technology development and production of epoxy resin, low viscosity, glass transition temperature Tg190 ℃.
For the insulation and to prevent electrochemical corrosion, in the outer surface of the carbon fiber composite core to be wrapped in glass fiber reinforced plastic or basalt fiber reinforced plastic.
According to the analysis, the strength of carbon fiber composite material aluminum stranded wire is 2 times of that of common wire. The carbon fiber composite material core is only 1/4 of the steel core, which can reduce the load of tower crane tower, shorten the installation period and improve safety. . In particular, there is no magnetic loss caused by wire or heat, transmission losses, energy-saving effect is considerable. The development of carbon fiber composite core wire will become a new economic growth point of the composite material industry.
Earlier this year, snowstorms in southern China to the national economy and the people's livelihood major disaster and economic losses, in some areas of the transmission tower distortion or even collapse of wounding. In view of this, China is developing a can increase the ampacity and reduce the tower load of new carbon fiber composite core conductor.