News from August 30, China Datang Xilinhaote Power Plant's 1000 kV supporting transmission project was successfully commissioned on the grid. This line is not only the first pilot demonstration project of the State Grid Corporation of China to apply the entire carbon fiber conductor line to UHV, but also the world's first UHV project with composite carbon core materials applied to the circuit. The transmission project of Datang Xilin Shengli Power Plant starts from Datang Xilinhot Power Plant and ends at Shengli 1000kV substation. It is erected in a single loop. The total length of the line is 14.591 kilometers. The conductor is a carbon fiber composite core conductor.
The carbon fiber composite core wire is an overhead bare wire that is impregnated with carbon fiber and glass fiber by epoxy resin, solidified to form a carbon fiber composite core, and twisted trapezoidal aluminum wire on the outer layer. It is made of carbon fiber composite core and outer layer aluminum wire concentrically twisted. Compared with traditional steel core aluminum stranded wire, it has achieved major breakthroughs in material selection scheme and structural design, with energy saving, large capacity, low sag, and high temperature resistance. , High strength, light weight, corrosion resistance, anti-icing and so on.
The carbon fiber composite core wire has a large current carrying capacity, and has excellent capacity increasing and margining characteristics. The carbon fiber composite core wire is increased in capacity by the following methods: it uses soft aluminum instead of hard aluminum, and the conductivity increases from 61% IACS to 63% IACS; compared with steel core aluminum stranded wire, carbon fiber composite core wire can operate at 160 ℃ Compared with the traditional round wire structure, the outer layer of the carbon fiber composite core wire adopts a wire structure. Under the same outer diameter, the filling rate of the aluminum cross section of the wire can be increased by 10% -30%; In the case of weight per unit length, the aluminum cross section of the carbon fiber composite core wire is increased by 10% -30% compared to the steel core aluminum stranded wire.
For the existing line reconstruction project, the carbon fiber composite core wire can be used to double the line transmission capacity without replacing the original pole tower. For new lines, especially new lines with unstable transmission capacity or unclear demand, the use of carbon fiber composite core conductors can provide a strong margin capacity to meet the growth requirements of regional transmission capacity in the future, and can adapt to large fluctuations in transmission capacity. Enhance the line's ability to respond to changes in transmission capacity.
Carbon fiber composite core wire is light weight, high strength and good safety. The density of ordinary galvanized steel wire is 7.8kg / dm3 and the strength is between 1240Mpa-1340Mpa, while the density of carbon fiber composite core is 2.0kg / dm3, which is 1/4 of the galvanized steel wire. The strength is divided into two grades: 2100Mpa and 2400Mpa. It can be seen that the carbon fiber composite core wire is light in weight, high in strength and better in safety.
The initial sag and sag change of the carbon fiber composite core wire are small, and the comprehensive economy is good. The carbon fiber composite core wire has a large tensile weight ratio, a small linear expansion coefficient, a small initial sag, and little sag variation during operation. Therefore, the height of the tower can be reduced, the number of towers can be saved, and the area of the tower foundation can be reduced to save land Resources to reduce the overall construction cost of transmission lines.
The carbon fiber composite core wire has small transmission loss and saves energy. With the same outer diameter and the same transmission capacity, the wire loss of the carbon fiber composite core wire is lower, which can save energy and reduce line operating costs.
Carbon fiber composite core wire has better anti-icing and anti-icing properties, and has good environmental adaptability. The carbon fiber composite core wire can transmit a larger load, the running wire temperature can be higher, and the outer diameter is smooth, so it has good anti-icing performance. At the same time, due to its high strength, the carbon fiber composite core wire has better resistance to icing and can be used in cold environments in the north.
Carbon fiber composite core wire has good environmental aging resistance and long life. Carbon fiber is resistant to corrosion. The carbon fiber composite core wire has extremely strong resistance to acid rain and other environments. It also avoids the electrochemical corrosion between the aluminum wire and the galvanized steel wire when the conventional wire is energized. It has excellent dielectric properties and long service life.