Aluminum foil for transformer winding has high electrical and thermal conductivity, its conductivity is as high as about 60% IACS, and the formability, weldability and corrosion resistance are all very good, which can well meet the performance requirements of aluminum foil for transformer.

Aluminum foil for transformers can be used in variable transformers, such as low-voltage or high-voltage transformer windings, high-frequency transformers, step-up or step-down transformers. The alloy can be used to meet the minimum industry requirements for ribbon conductors and is tightly controlled to ensure smooth edges, essentially burr-free, and the availability of ribbon sizes is identical to the availability of standard copper wire sizes.

Aluminum windings have been commonly used in dry-type transformers. Aluminum tape can replace copper conductors in distribution transformers.

Product description of aluminum foil for transformer windings

Chemical composition of aluminum foil for transformer windings

 

 

 

Advantages
For example, the main advantage of using aluminum foil rather than copper foil in transformers is weight reduction. Copper has a density of .32117 pounds per cubic inch, while aluminum has a density of .09765 pounds per cubic inch. For a given winding volume, an aluminum winding will weigh one-third as much as copper. However, aluminum is only 60% as conductive as copper. If the winding volume were increased by 40% to increase the conductivity of aluminum to the level of copper, the aluminum coil would still weigh only 42% of the equivalent copper coil.

Applications
Power transformers
Distribution transformers
Dry-type transformers
Low frequency transformers




Considerations
Lower electrical conductivity of aluminum conductors compared to copper: in order to achieve the same resistance, aluminum conductors need to have a larger cross-sectional area than copper conductors, which may require more space.
Mechanical strength: aluminum is not as strong as copper, which makes it more susceptible to mechanical damage during winding and handling.
Thermal Expansion: Aluminum has a higher coefficient of thermal expansion compared to copper, which can lead to mechanical stresses in the winding during temperature changes.
Connector and joint issues: Special care is needed when connecting aluminum to other materials to avoid galvanic corrosion and ensure a reliable electrical connection. Typically, aluminum requires crimped or bolted connections rather than soldered connections.

Techniques for using aluminum foil in transformer windings
Layer winding: Aluminum foil is wound in layers separated by an insulating layer to form a compact and efficient winding structure. This technique is particularly effective in reducing eddy current losses.
Interleaved winding: In some designs, the aluminum foil is interleaved with the insulating material to improve voltage distribution and reduce dielectric stress.
Automated Winding Machines: Specialized winding machines are often used to precisely wind aluminum foil, ensuring consistent tension and alignment, which is critical to performance and reliability.

Comment est fabriquée la feuille d'aluminium ?