A Review of Thermal and Electrical Designs for Drytype Transformers and Future Perspectives

Dry-type transformers are used as alternatives to liquid-immersed transformers in applications with concerns about fire safety and environmental impact. Progress made in the past several decades has resulted in the development of dry-type transformers with voltages up to 145 kV and power levels up to 63 MVA. However, the expansion results in challenges associated with both thermal and electrical designs. This paper provides a critical review of the latest developments in thermal and electrical designs for dry-type transformers. Furthermore, the current technical challenges are summarized and the research opportunities for the next-generation transformers are discussed.