Accurate hot spot modeling in a power transformer leading to improved design and performance

Power transformers are key components in the distribution of electrical energy, so it is very important to protect them from a breakdown. Hot spot temperature is an important parameter in aging of a transformer so it´s both for customers and producers of transformers very useful to have an accurate measurement or computer model prediction of the hot spot temperature. This paper describes a computer model, which can predict hot-spot temperatures for different types of cooling regimes and transformer winding geometries. The program can be used as a design tool, to verify if the hot spot temperature is not too high and to verify the influence of different parameters (winding geometry as well as cooling method or number of radiators) on the temperatures. This knowledge can be shared with the customers allowing improved loading conditions