Electrical Properties of Aluminum Alloy Cables

Electrical Properties of Aluminum Alloy Cables

1. Cable current carrying capacity

When the cross-sectional area of the alloy conductor is 1.5 times that of the copper, the electrical properties of the alloy conductor and the copper conductor are the same, achieving the same carrying capacity, resistance and pressure loss.

_The resistivity of aluminium alloy is between aluminium and copper, slightly higher than that of aluminium, but lower than that of copper. Under the same cut-off flow rate, the weight of aluminium alloy conductor of the same length is only half that of copper. If the conductivity of copper is calculated as 100%, the conductivity of alloy conductor is about 61.2%, the specific gravity of alloy is 2.7, and the specific gravity of copper is 8.9, then (8.9/2.7)* (0.612/1) = 2, that is, the resistance of two units of weight of copper is the same as that of one unit mass of alloy. Therefore, when the cross-sectional area of alloy conductor is 1.5 times of copper, its electrical properties are the same. Same, that is, the same cut-off flow, resistance, and voltage loss as copper.

There are many factors affecting the cut-off flow of power cable, such as line characteristics (such as working electricity, current type, frequency, load factor); structure of wire and cable (such as structure of conductive core, number of core, type of insulation material, structure and material of shielding layer and inner and outer protective layer, total outer diameter); laying conditions (such as laying in air, pipeline). Medium laying, direct burial laying, underground ditch laying, underwater laying; maximum permissible working temperature of conductor core and surrounding environmental conditions (such as air and soil temperature, soil thermal resistance coefficient, adjacent effect of surrounding heat sources), etc.

2. Reducing the External Section of Cables

In the production process of aluminium alloy cable, the most advanced compaction technology in Germany can make the filling coefficient of conductor reach 93%. And the aluminium alloy cable is made of silane crosslinked polyethylene, which only needs 2/3 of the thickness of polyvinyl chloride to far exceed the conventional insulation performance. The filling coefficient of copper can only reach 80%. The common insulation is polyvinyl chloride. Therefore, the outer diameter of aluminum alloy cables can only be increased by 11% on the basis of copper cables, so that they can have the same electrical properties as copper. It can be seen that the use of aluminium alloy cable does not need to change the original copper cable pipeline design. (General designer design laying pipe size is 150% of the copper cable, so pipe piercing is not a problem. )

3. Reducing Cable Loss

Non-magnetic material, will not produce eddy current, can reduce line losses. Aluminum alloy with armor lock material is non-magnetic material, even if there is three-phase unbalanced current, it will not produce eddy current, which can reduce line losses.