Numerical thermofluid analysis of a power transformer disc-type winding

This contribution describes the early results of a long term R&D collaboration established between IREQ and EFACEC. This partnership focuses on disc-type windings, which are the most common geometry used in real core-type transformers. One of the main objectives so far has been the comparison of two different in-house thermal models (THNM1 and THNM2) with the most accurate numerical approach, namely a tridimensional CFD model. Both codes proved to be robust and able to predict the thermal behavior, particularly for ON conditions. From this comparison, it is currently observed that THNM1 predictions tend to be closer to CFD flow patterns and disc temperatures, seemingly due to its CFD calibrated friction and convection heat transfer coefficients expressions. Further analysis will be performed in the future to compare such in-house models and CFD with measurements obtained under a tightly controlled experimental environment.