1.What is carbon fiber material?
Carbon fiber is a new type of fiber material with a high carbon content, high strength and high modulus. It has the advantages of light weight, high strength, high temperature resistance and low thermal expansion. These characteristics are perfectly matched for the core of conductors, all being advantages.
2.What are the characteristics of the wires?
The conductors of overhead transmission lines mainly need to possess two properties: mechanical performance and electrical performance! Mechanical performance is called “rigidity”, and electrical performance is called ‘flexibility’. The term ‘a combination of rigidity and flexibility’ means having both good mechanical performance and electrical performance at the same time.
3. What is carbon fiber conductor?
Carbon fiber conductor is fully known as carbon fiber composite core overhead conductor (ACCC Conductor), which refers to the overhead conductor made by concentrically stranding multiple soft aluminum single wires or heat-resistant aluminum alloy single wires with a carbon fiber composite core.
4. What are the main features of carbon fiber composite core conductors?
Light weight, high strength, and low sag: The density of ordinary galvanized steel wire is 7.8 kg/dm³, and its strength is between 1240 MPa and 1340 MPa. In contrast, the density of carbon fiber composite core is 2.0 kg/dm³, which is one-fourth that of galvanized steel wire. The strength of carbon fiber composite core is divided into two grades: 2100 MPa and 2400 MPa. It is evident that carbon fiber composite core conductors are light in weight and high in strength. It is precisely because of their light weight and high strength that the sag of the line is small. Carbon fiber composite core conductors have a significant low sag characteristic. Under high-temperature conditions, the sag is less than half that of steel-cored aluminum stranded wire, effectively reducing the insulation space corridor of overhead lines.
5. What are the disadvantages of carbon fiber conductors?
1. As a composite material, the carbon fiber core has poor durability and is prone to brittle fracture. Its reliability is inferior to that of conventional conductors, and the consequences of a breakage are severe.
2. During production, transportation, installation, and operation, the carbon core of carbon fiber composite core conductors is prone to damage and difficult to detect, which directly affects the safe operation of the line.
3. Carbon fiber core conductors are relatively expensive, being 2 to 2.5 times the price of conductors with steel cores of the same specification.
6. Why is carbon fiber composite core conductor a heat-resistant conductor.
1. The maximum operating temperature of the carbon fiber core can reach 180 ℃ or even higher, while the long-term operating temperature of hard aluminum wire is only 70 – 80 ℃. Therefore, the carbon fiber core can be combined with soft aluminum, which is more resistant to high temperatures. The electrical conductivity of ordinary steel core aluminum stranded wire is 61% IACS, while that of energy-saving composite conductors is above 63% IACS.
2. Carbon fiber conductors do not have magnetic loss and thermal effect caused by steel wire materials. Under the condition of the same cross-sectional area and the same load transmission, they have a lower operating temperature and can reduce transmission loss by 6%. When the diameter is the same (28.14mm), the aluminum cross-sectional area of carbon fiber conductors is 1.29 times that of conventional ACSR conductors, thus increasing the current carrying capacity by 29%.
3. Due to the limitations of softening characteristics and sag characteristics, the working temperature of conventional ACSR conductors can only be increased to a very limited extent, and the increase in current-carrying capacity mainly relies on increasing the conductor cross-section. However, the softening characteristics and low sag characteristics of carbon fiber conductors are comparable to those of heat-resistant aluminum alloy conductors and invar heat-resistant aluminum alloy conductors. But its resistance is relatively small. Therefore, under the same conductor outer diameter, due to the increase in aluminum cross-section and the increase in the working temperature of the conductor (150~180℃), the comprehensive current-carrying capacity of the conductor can theoretically be increased to twice as much. The short-circuit allowable temperature of carbon fiber conductors can even reach 200℃.
In conclusion, carbon fiber conductors are particularly suitable for capacity expansion and renovation projects. By taking advantage of the good sag characteristics, large transmission capacity and low conductor load of carbon fiber conductors, the capacity expansion and renovation projects do not need to build new towers, reducing the investment in the main body.
Post time: Jan-07-2025