Aluminium transformer foil VS Copper foil

Aluminum foil and copper foil can be used in the dry type transformer winding. In the advanced countries, the aluminium transformer foil are commonly used instead of copper foil for the low price and friendly to the environment. Besides of these advantages, the transformer aluminium foil also have superior features on the performance than copper foil.

Technical performance comparison of dry-type transformer coils made of aluminium foil and copper foil:
1. The mechanical strength of aluminium is lower than that of copper, but it has no effect in dry-type transformers.
While winding the high-voltage coil, a glass fiber mesh skeleton is installed inside and outside the coil, and since the vacuum casting method is adopted, no voids and pores are left in the coil, the glass fiber, the resin are combined, the transformer aluminium foil and the insulating film are combined tightly as a whole, these measures have compensated for the weakness of the mechanical strength of the aluminium foil. The fabricated aluminum foil high voltage coil is sufficient to resist the mechanical stress generated during a sudden short circuit.
2. Aluminum has a lower electrical conductivity than copper, the specific gravity is lower than copper. It is more suitable as a conductor for dry-type transformer coils.
Since aluminium foil for transformer has a lower electrical conductivity than copper, in order to obtain the same resistance value, aluminum must have a cross-sectional area of 1.64 times that of copper. However, the density of aluminum is only one-third of that of copper, so when the same resistance value and the same capacity of electrical energy are transmitted, the weight of aluminum is only one-half of that of copper, it is better to meet the requirements of lightweight. Under normal circumstances, material costs of the aluminium transformer foil can also be reduced, and its price performance ratio is much better than that of copper coil dry-type transformers.