Design of distribution transformers – e-lesson #7: Thermal analysis for power transformers

This is the seventh lesson in the Design of distribution transformers course, conducted on the Intermediate level. Here you can save your seat.

This lesson focuses on the thermal analysis of power transformers, particularly oil-filled distribution transformers. The speaker, Mario, explains that thermal analysis is a complex topic, as it is difficult to accurately model the behavior of the various materials in a transformer using mathematical formulas. However, temperature is a crucial factor in transformer design and lifespan. The lesson covers the exponential relationship between temperature and insulation aging, highlighting how small temperature differences can significantly impact a transformer's lifetime. It then discusses the three main heat transfer mechanisms - conduction, convection, and radiation - with convection being the most important for transformers. Practical considerations like fluid velocity, cooling channel design, and radiator selection are explored. The speaker emphasizes the need for creative problem-solving by designers to balance cost, efficiency, and compliance with standards. Overall, the lesson frames the key thermal concepts that will be expanded upon in future sessions.