aluminum foil strip


Aluminum for transformer winding

Source:Original Editing:frank Time:2022-08-09 18:06
As far as 50 years ago, aluminum foil windings have been used in transformers (mainly distribution transformers). The rated power of the winding is usually less than 2.5 MVA and the rated voltage is 3.6-36 kV. It is used as an oil immersed or air-cooled transformer. Aluminum winding can also be used in very small (several volt Amperes) and large (25-63 MVA) rated power transformers. Several structural components of the high-power transformer designed at present are also made of aluminum, including wire clamp plate, shell, electromagnetic shielding surface, etc., which can reduce the additional loss.

The economy of application in transformer winding is determined by the price ratio of aluminum to copper winding. Considering the manufacturing cost, if the manufacturing cost of copper winding after the rated power is reduced is still higher than that of aluminum winding transformer with the same rated power, it is more economical to use aluminum.
This kind of transformer is economical when the production cost and operation cost of the transformer are minimal. The most economical current density of copper winding is 2.5-3.5 A / mm2, and that of aluminum winding is 1.5 A/mm 2. In the air-cooled transformer, the winding occupies most of the transformer space, so the use of aluminum winding is economical and the production cost is small.
From the perspective of load and size, the best aluminum winding material is semi-rigid wire. Recently, dry-type or oil immersed transformers with rated power of megavolt amperes have adopted aluminum foil windings. It has the advantages of good heat dissipation in the winding, high resistance to short circuit current, improved voltage distribution caused by impulse voltage, and easy automation in the manufacture of this winding