Abstract:The calculation of eddy current loss of power transformer is of great significance to improve the stability, safety, and efficiency of the transformer. Firstly, from the perspective of the three phase three limb transformer core topology, an electromagnetic model of a three-phase three-limb transformer considering winding coupling is derived from unified magnetic equivalent circuit (UMEC). Secondly, combine the electromagnetic model with the empirical formula of eddy current loss for power transformer, the estimated value of the eddy current loss involving the fuel tank and the clamping part in the transformer could be obtained. Finally, by using FLUX3D software, a finite element model of the transformer considering the eddy current loss for fuel tank and clip is established. The eddy current loss results obtained in this paper are compared with the numerical results by the finite element software, which proves the effectiveness of research method and software proposed in this paper. The research on the modeling and eddy current loss calculation method based on the software has a certain prospect for the development, production, and application of power transformer.