Can Aluminum Foil Be Used for Transformer Windings?

Yes — aluminum foil is not only suitable but increasingly preferred for transformer windings, especially in dry-type and distribution transformers. With the push for automation, weight reduction, and cost control, aluminum foil windings offer outstanding technical and economic benefits.

Advantages of Aluminum Foil Windings

 Better Space Utilization

Foil windings wrap tightly around the transformer core, minimizing air gaps and improving magnetic circuit efficiency. This compact structure also enhances heat transfer and insulation design.

 Reduced Manufacturing Complexity

Aluminum foil allows for fully automated winding processes, improving production speed and consistency. Unlike round wire, foil does not require complicated layering or tension control.

 Superior Short-Circuit Strength

With a wide, flat surface area, foil distributes current more evenly and withstands mechanical forces during short-circuit events better than traditional wire windings.

 Enhanced Cooling Performance

The large surface area of foil windings improves thermal dissipation. This helps keep temperature rise under control, extending the transformer's lifespan.

 Lower Material Cost and Weight

Aluminum is significantly cheaper and lighter than copper. Foil designs further reduce metal usage by enabling thinner, flatter winding profiles without sacrificing performance.

Considerations When Using Foil Windings

• Requires appropriate insulation film (e.g., polyester, polyimide)
• Proper bonding/welding techniques to manage oxide layers
• Accurate treatment of lead-outs and tap connections

Common Applications

• Dry-type transformers
• Oil-immersed distribution transformers
• Choke coils and reactors
• EV charging equipment

Aluminum foil windings are not a compromise — they are a modern engineering solution that supports efficiency, automation, and sustainability in transformer design.