In addition, copper cable also has excellent tensile, shrinkage, creep and fracture resistance, as well as excellent flexibility, corrosion resistance and ductility, which can meet the long-term stable and reliable operation of high-speed rail in various climatic environments, which is beyond the reach of aluminum cable.
After long-term use and stretching, the current carrying capacity and conductivity of aluminum conductor will decrease, which will easily lead to deformation and loose connection, and then oxidation, arcing and overheating will occur, which is absolutely not allowed for high-speed rail that needs absolute safety.
Characteristics of UHV transmission:
Use 1000 kV and above to transmit electric energy. Ultra-high voltage transmission is developed on the basis of ultra-high voltage transmission, and its purpose is still to continue to improve transmission capacity, realize high-power medium and long-distance transmission, realize long-distance power system interconnection and build a joint power system.
UHV transmission has obvious economic benefits. It is estimated that the transmission capacity of1150 kV transmission line can replace 5 ~ 6 500 kV lines or 3 750 kV lines; It can reduce one-third of the tower materials, save one-half of the wires, and save the cost of power grid including substation 10 ~ 15%.
1 150 kv high-voltage line corridor is only about a quarter of the corridor required for 500 kv lines with the same transmission capacity, which will bring huge economic and social benefits to countries and regions with dense population, precious land or difficult corridors.