Power Transformer Winding Thermal Analysis ...

Power transformer outages have a considerable economic impact on the operation of an electrical network. In order to draw maximum power from transformers and, at the same time, avoid thermal mishaps, it is essential to carefully study its thermal behavior. Furthermore, an accurate computation of the hottest spot temperature (HST) helps in a realistic estimation of the reliability and remaining life of the transformer winding insulation. This paper presents steady state temperature distribution of a power transformer layer-type winding using conjugated heat transfer analysis, therefore energy and Navier-Stokes equations are solved using finite difference method. Meanwhile, the effects of load conditions and type of oil are investigated using the model. Oil in the transformer is assumed nearly incompressible and oil parameters such as thermal conductivity, special heat, viscosity, and density vary with temperature. Comparing the results with those obtained from finite integral transform checks the validity and accuracy of the proposed method.