(1) Resistivity Aluminum alloy conductor resistivit […]
Aluminum alloy conductor resistivity and aluminum, about 1.68 times the copper, copper core cable because of the low resistivity, in the same section, the copper cable voltage drop is small. But generally in engineering applications, the aluminum alloy cable in order to achieve the same current carrying capacity, zoom section, the voltage drop quite.
Copper density of about 8.9t / m3, aluminum alloy density and aluminum equivalent, about 2.7t / m3, that is, the weight per unit area, the weight of copper is about 3.3 times the aluminum alloy.
(3) Conductive capacity
(8.9 / 2.7) × (0.612 / 1) = 2, that is, the conductivity of 2kg copper is equivalent to that of 1kg aluminum alloy, since the conductivity of the conductor is proportional to the conductor cross section. In addition, considering the density, the alloy cable cross-sectional area of about 1.5 times the copper cable, the electrical performance of the same. Therefore, in the actual cable selection, the aluminum alloy cable section is about 1.5 times the copper cable, the weight of about half of the copper cable.
(4) short-circuit thermal stability
According to the "Power Engineering Cable Design Code" GB50217-2007, according to the short-circuit thermal stability of the cable conductor to allow the minimum cross-section of the formula is as follows:
Calculated (calculated in this paper), available, copper cable thermal stability coefficient of copper = 13700, aluminum alloy cable thermal stability coefficient of C aluminum = 9000, through the same short-circuit current, and short circuit duration is equal to the case , Set S copper ≥ S benchmark, then S aluminum ≥ 1.52S benchmark, that is under the same conditions, the aluminum alloy cable cross section must be copper cable section of 1.52 times and above.
In summary, the aluminum alloy cable selection, the cross section should consider amplification, when the amplification of about 1.5 times, the main parameters of the basic and copper cable quite.