Analytical and Numerical Thermal Modelling of a Low Power Transformer

In past decades, thermal modelling of electric machines was overlooked and based on empirical experience. Due to modern requirements, using novel materials and innovative configurations, the thermal model became a crucial component in the modern design process. The thermal modelling can be performed by analytical methods, as the thermal resistance network (TRN) or by numeric methods as the finite element analysis (FEA). This work presents a methodological approach to thermal modelling, addressing both approaches and applying them to a study case of a low power shell-type single-phase transformer. The results from both approaches are compared with experimental results, achieving relative errors of 5.70% and 21.24% on the determination of windings' temperature, for the FEA and TRN model respectively, which helps define model improvements.