Improved thermal model of air-insulated power transformers considering the effective thermal conductivity

Abstract

Transformers play a key role in transmission and distribution networks, ensuring efficient energy delivery with minimal losses. Optimal design is essential for efficient operation, and accurate thermal models with low computational demands are highly attractive for this purpose. This study highlights the critical role of predicting hotspot temperatures in transformer windings for accurate power transformer design. A thermal resistance network is used to model various transformers, which facilitates the estimation of the effective thermal conductivity that accurately reflects the real temperature gradient. Experimental measurements with interlayer thermocouples estimate the internal thermal gradient, enhancing the understanding and modeling of transformers’ thermal behavior, ultimately leading to improved design and performance.