At present, overhead cables are used to transport electricity over long distances. Conventional cables are mostly aluminum conductor steel reinforced (ACSR). Since the 1990s, carbon fiber composite cores (aluminum conductor composite core) have been used as the core bar of cables. ACCC has the following advantages over traditional conductors.
1. High strength and lightweight.
The tensile strength of ordinary steel wire is 1240~1410MPa, while the carbon fiber composite core of the ACCC conductor is twice the former, and its specific gravity is only 1/4 of steel. The weight per unit length of ACCC conductors of the same specification is 10%~20% lighter than conventional ACSR conductors. This allows the tower span of overhead cable to grow, reducing the number of towers by about 16% while reducing the footprint.
2. High conductivity and low transmission loss.
Under the same outer diameter, the cross-sectional area of ACCC’s aluminum strand is 1.29 times that of conventional wires. Therefore, the load capacity is increased by about 29%. Because ACCC wire does not have the magnetic loss caused by the wire material and the resistance heat effect. In addition, it has a lower operating temperature for the same load, which reduces transmission losses by about 6%. Also, because ACCC uses trapezoidal aluminum wire, its appearance is smoother than ACSR’s round aluminum wire. The surface roughness coefficient is improved, thus increasing the corona onset voltage of the wire and reducing the corona loss.
3. Low arc sag, reducing sag by more than twice.
ACCC wire has significantly low relaxation characteristics compared to conventional wire. Under high-temperature conditions, the arc sag is less than 12% of steel-core aluminum-stranded wire. It can effectively reduce the insulation space of the overhead line corridor, improve the safety and reliability of the wire operation.
4. Corrosion resistance.
ACSR’s aluminum wire and steel core due to long-term exposure to the air. The surrounding environment will corrode the metal material, thus reducing the strength of the wire and affecting the life of the wire. Carbon fiber composite core does not rust, corrosion resistance, overcoming the corrosion of galvanized steel stranded wire core. And it also avoids the electrochemical corrosion problem between the aluminum wire and galvanized steel wire when the conductor is energized. Better solve the aging problem of long-term operation of the wire, the service life is higher than the ordinary wire twice.
