Aluminum Strip for Transformer Winding

Aluminum strip used for transformer windings is an essential component in the manufacturing of power transformers and can be used as conductors for both dry-type and oil-immersed transformers. Compared to copper alternatives, these aluminum strips are favored for their excellent conductivity, lightweight properties, and cost-effectiveness.

Transformer winding aluminum strip, also known as transformer winding aluminum foil, is mainly used in the production of dry-type transformers. Common aluminum alloys used for transformer windings include 1060, 1050, 1070, 1350, etc., with a temper of O. The thickness typically ranges from 0.2mm to 3.5mm.

The aluminum strip is a key component in transformer windings, offering advantages such as cost-effectiveness, lightweight design, and high conductivity.

Features of Transformer Winding Aluminum Strips

• Burr-Free: The aluminum strips undergo precision processing, resulting in an extremely thin thickness and a smooth, flat surface without any burrs, ensuring safety and reducing losses.
• Round Edge Design: The edges of the aluminum strips are specially treated to form rounded edges, preventing mechanical damage or electrical insulation issues during use, enhancing safety and reliability.
• High Conductivity: Made from high-purity aluminum, the strips exhibit excellent electrical conductivity, which can effectively reduce energy loss and improve transformer efficiency.
• High-Purity Material: The aluminum strips have extremely high purity, typically using aluminum with a purity of over 99.6%, ensuring excellent electrical performance and stability, suitable for demanding electrical applications.
• Good Flexibility: The aluminum strips undergo full annealing treatment, providing them with good flexibility, making them easy to process and shape in transformer windings, while also enhancing service life and performance stability.
• High Strength Standards: While ensuring high conductivity, the mechanical strength of the aluminum strips meets high standards, capable of withstanding various stresses and loads during manufacturing and operation, ensuring long-term stable operation of the transformer.

Electrical Conductivity of Aluminum Foil Strips for Transformers

• 1050: Better than 60% IACS.
• 1060: Better than 61.5% IACS.
• 1070: Better than 62.7% IACS.
• 1350: Better than 62% IACS.

Transformer Winding Aluminium Strips Specifications

Advantages of Using Aluminum Strips for Transformers

• High Conductivity: Ensures efficient power transmission, reducing energy loss within the transformer.
• Lightweight: The low density of aluminum simplifies handling and reduces the overall weight of the transformer, which is beneficial in various installation situations.
• Corrosion Resistance: Aluminum naturally forms a protective oxide layer, enhancing durability and extending the transformer’s service life.
• Thermal Conductivity: Helps dissipate heat efficiently, maintaining optimal operating temperature and preventing overheating.
• Cost-Effective: The affordable price of aluminum makes it a practical choice for transformer windings, balancing performance and material costs.
• Good Flexibility: The aluminum strip has excellent flexibility and can be processed into ultra-thin sheets less than 0.08mm in thickness, which enhances its adaptability during transformer winding, allowing it to accommodate complex coil structures and improving production efficiency.
• Easy to Remove Oxide Layer: During the transformer winding process, the oxide layer on the aluminum strip is easy to remove without affecting insulation performance, ensuring electrical insulation and safety, and improving long-term stability.
• Good Ductility: The aluminum strip has excellent ductility with high elongation. It won’t break even when stretched over 2mm, enhancing its resistance to stress during processing and helping prevent damage to transformer windings during use.
• Strong Malleability: The aluminum strip has good malleability and can be shaped into various forms and sizes according to design requirements. This flexibility makes it an ideal winding material for various transformer designs.
• Strong Interlayer Adhesion: The aluminum strip has good interlayer adhesion, enhancing the structural stability and electrical performance of the transformer, ensuring reliability and durability during operation.

Aluminum Strips for Transformers Chemical Composition

1050 O Aluminum Strips Chemical Composition

1060 O Aluminum Strips Chemical Composition

1070 O Aluminum Strips Chemical Composition

1350 O Aluminum Strips Chemical Composition

Transformer Aluminum Strip Thickness Tolerance

Transformer Aluminum Strip Width tolerance

Transformer Aluminum Strip Burrs and collapse

Types of Aluminum Strips for Transformers

Transformer Aluminum Strip 1050 O

The 1050 aluminum foil strip contains 99.5% aluminum, offering excellent conductivity and flexibility. It is fully annealed in the O temper, making the foil softer and easier to process. It is commonly used in transformer windings and is suitable for applications requiring high conductivity and good ductility.

The 1050 O aluminum strip is one of the most commonly used materials in transformers. It is frequently used as support material in transformer windings, which helps to reduce transformer losses and improve performance.

The thickness of the 1050 O aluminum strip used in transformers generally ranges from 0.1mm to 1mm. It is available in single or double-layer structures, which can effectively reduce magnetic leakage in coils and enhance insulation performance.

Transformer Aluminum Strip 1060 O

The 1060 aluminum foil strip has an aluminum content of up to 99.6%, offering excellent electrical conductivity and high corrosion resistance. In the O temper, 1060 aluminum foil is softer and easier to shape, making it suitable for winding transformer coils, especially where strict electrical and mechanical performance is required.

1060 O aluminum alloy has good plasticity but lower strength compared to other alloys. It is mainly used in various high and low voltage electrical devices, such as transformer windings.

Transformer Aluminum Strip 1070 O

The 1070 aluminum foil strip is based on high-purity aluminum with 99.7% aluminum content. It has outstanding conductivity and good flexibility and durability. The 1070 O temper foil can form stable coil structures during transformer winding, making it suitable for transformer designs that require higher conductivity and ductility.

The 1070 O aluminum foil for transformer windings can be used in dry-type transformers, oil-immersed transformers, and reactor windings.

The 1070 O aluminum foil for transformer windings has excellent heat dissipation properties, and does not increase the temperature rise of the coil during long-term operation, thus extending the coil's service life. Using 1070 O aluminum foil for transformer windings can reduce the cost of batch manufacturing transformers by 15%.

Transformer Aluminum Strip 1350 O

The 1350 aluminum foil strip is a high-purity aluminum foil with an aluminum content exceeding 99.5%, widely used in transformer windings. The 1350 O temper foil, after annealing, has excellent plasticity and flexibility, meeting the high conductivity and mechanical stability requirements for transformer winding materials.

The 1350 O aluminum foil for transformer windings is widely used in the transformer industry, including oil-immersed transformers and dry-type transformers.

The 1350 O aluminum foil for transformer windings is available in both bare and coated types. The bare type is mainly used as winding material for oil-immersed transformers, while the coated type is primarily used as interlayer insulation material.

Transformer Winding Aluminium Strip Superior to Copper

Haomei Transformer Winding Aluminium Strips Manufacturing and Quality Standards

Edge Quality:

• Burr-Free: Burr height ≤ 0.03–0.05 mm (to prevent insulation damage).
• Rounded Edges: Improves winding efficiency and safety.

Tolerance:

• Thickness: ±0.01–0.08 mm (varies with thickness range).
• Width: ±0.1–2.0 mm (the narrower the strip, the tighter the width tolerance).
• Certification: Complies with GB/T 3190-1996 (Chemical Composition) and YS/T 713-2009 (Electrical Performance).

Application Scenarios of Transformer Aluminium Strips

Main Material for Large Transformer Coils

Aluminium strips are primarily used for winding transformer coils, helping to improve the efficiency and reliability of transformers. Their properties make them suitable for various types of transformers, including distribution transformers and power transformers.

• Dry-Type Transformers: Due to their light weight and corrosion resistance, aluminium strips are the preferred choice for windings.
• Oil-Immersed Transformers: The usage rate is continuously increasing, as they save costs and reduce maintenance.
• Distribution: Used in transformers up to 4 MVA.

Applications in Solar and Power Industry

Aluminium strips, as conductive materials for the high and low-voltage windings of dry-type transformers, are suitable for use in the power industry, solar energy, and other fields.

Other Industries that Use Transformer Aluminium Strips

Processing and Treatment of Transformer Aluminium Strips

Processing of Transformer Aluminium Strips

• Raw Material Preparation and Heating: First, the aluminium ingots are placed in a furnace and heated. The furnace temperature gradually increases to an appropriate range to melt the aluminium. Alloying elements are added during the melting process to remove impurities and enhance the purity and performance of the aluminium.
• Casting and Billet Cutting: After impurities are removed from the molten aluminium, it is cast into aluminium billets, which are then cut into aluminium plates of the specified thickness for further rolling processes.
• Rough Rolling: The cut thick plates are sent to the cold rolling machine for rough rolling. The cold rolling process gradually reduces the thickness of the aluminium plates and initially adjusts the material’s mechanical properties to meet the requirements for the subsequent hot rolling.
• Hot Rolling and Finishing: The rough-rolled aluminium plates are sent to the hot rolling mill for further processing. The hot rolling process, conducted at higher temperatures, effectively enhances the ductility and toughness of the aluminium strips, resulting in finished strips that meet the specifications.
• Annealing: After rolling, the aluminium strips undergo an annealing process. Annealing involves heating the material to a certain temperature and maintaining it for a period to relieve internal stresses, improve ductility, flexibility, and corrosion resistance, ensuring the stability of the aluminium strip’s performance.
• Cutting and Shaping: The edges of the annealed aluminium strips are trimmed to ensure accurate dimensions and smooth edges.
• Packaging and Shipping: Finally, the finished transformer aluminium strips undergo quality inspection and are coiled and packaged according to customer requirements. Once the packaging is complete, the aluminium strips are safely transported to the designated location for use.

Manufacturing Considerations

When selecting aluminium strips for transformer windings, factors such as alloy grade, thickness, width, and edge treatment must be considered to meet the specific transformer design requirements. Proper annealing and surface treatment can further improve performance and extend service life.

Transformer aluminium strips offer a combination of electrical efficiency, mechanical strength, and economic feasibility, making them the preferred material for transformer manufacturing.

How to Select Aluminum Strips for Transformers?

Conductivity

Electrical conductivity is one of the most important properties of transformer aluminum strips, typically requiring a conductivity of 60% IACS or higher. The conductivity of the aluminum strips directly affects the efficiency and stability of the transformer. Therefore, when purchasing, ensure that the selected strips meet the standard conductivity to guarantee the transformer’s operational efficiency.

Mechanical Properties

Mechanical properties such as tensile strength and elongation are also key factors to consider. Transformer aluminum strips need to have good flexibility and appropriate strength to avoid breaking or deforming during winding. Therefore, ensure that the strips have been adequately annealed (e.g., O temper) to provide excellent ductility and good processing performance.

Surface Quality

The surface quality of the transformer aluminum strips directly impacts the smoothness of the winding process. The surface should be smooth, free of oil, scratches, oxidation spots, or other defects. High surface quality not only improves the appearance of the transformer but also avoids winding issues caused by defects. Therefore, carefully inspect the surface condition of the aluminum strips and request relevant quality inspection reports from the supplier.

Size Specifications

Select the appropriate thickness and width of the aluminum strips according to the transformer design requirements. Common thicknesses for transformer aluminum strips range from 0.2mm to 3.0mm, with widths customizable based on needs. Ensure that the size tolerances are within a reasonable range to maintain processing accuracy and performance stability of the transformer.

Supplier Reputation

Choose suppliers with a good reputation and stable, long-term supply capabilities. High-quality suppliers not only provide excellent products but also offer comprehensive after-sales service and technical support, ensuring stability and quality throughout the transformer production process.

Testing Reports and Certifications

Transformer aluminum strips typically need to comply with industry standards, such as ASTM or GB, to ensure quality. Request detailed testing reports from the supplier to ensure that the products meet requirements for mechanical properties, conductivity, and surface quality.