Copper vs. Aluminum Windings in Dry-Type Transformers: A Comprehensive Study of Losses, Size, and Technical Attributes

Dry-type transformers are widely used in various applications, from power distribution systems to industrial units. A pivotal consideration in transformer design is the choice of conductor material, with copper and aluminum being the primary options. This manuscript presents a comprehensive experimental comparison between copper and aluminum windings in dry-type transformers, aiming to provide insights into their respective performance characteristics, efficiency, and weight. The study commences with a detailed overview of the properties and advantages of copper and aluminum as conductor materials. We explore factors such as electrical losses, and physical properties, which influence the efficiency, size, weight, and reliability of transformers. Using copper windings instead of aluminum in dry-type transformers for non-specific power needs does not offer any technical advantage. The thermal expansion coefficient of a copper conductor is less compatible with the resin than the aluminum conductor.