Realization of electromagnetic field and thermal analysis of transformers using finite elements

In the design of power transformers, the system and the electrical power that the transformer will transfer to the system are important for the continuity and safety of the system. It is necessary to know the mechanical, electrical and magnetic properties of a transformer in the production process. In order for the transformers to be designed to operate at targeted values and efficiency, it is important to model them with a reliable simulation program, to provide test criteria and to minimize the problems that may arise later. In this thesis, ANSYS @ Maxwell simulation program, which is widely used in transformer simulation and which performs solutions based on the Finite Elements Method (FEM), was used to analyze multiple physics analysis of transformers. For this purpose, the material proportions of the transformer, geometry of the model, heat transfer coefficients for each surface, ferromagnetic effects, properties of magnetic materials and non-linear behaviors are defined as input values in the program environment. For accurate results of magnetic field and temperature distributions, electromagnetic and heat flow field equations are solved using numerical methods and analytical methods. The highest temperature of the core is obtained in regions where the magnetic flux density is maximum. It was determined that excessive heat occurred in these regions and accordingly, there were many losses. The performances of the models were compared with the transformer performance determined analytically and available experimentally determined performance, and the results obtained were found to be in good agreement with the literature. The optimum values for the windings and cores have been calculated, the electromagnetic forces formed in the windings have been determined, the heat distribution in the winding and core has been obtained, the electrostatic field distributions have been examined, the electric field distribution in the case of lightning impulse has been examined, the problematic areas have been determined and the total losses and thermal effects of different transformer models under different conditions have been obtained. The method used provided benefits such as, reducing costs, simplifying the production process and increasing technical performance.