Comparison of two- and three-dimensional Magnetic Field Calculation for large Power Transformers

To investigate the limits of twodimensional (2D) models for magnetic field calculation a 400 MVA network power transformer has been simulated either in a rotational symmetric (2D) model as well as in a model of three dimensions (3D). The model has been kept as simple as possible to demonstrate the capability of application in daily business. The comparison between the 2D and 3Dmodel demonstrates the ability of the rotational symmetric consideration for simulating magnetic field characteristics as well as the limits of such a simplified concept of modeling. The results for the 2D-model are quite similar to those of the 3D calculation for the major part stray field path. Especially, the flux density on straight lines starting from the center of a limb is nearly identical for both models. Unfortunately, there are significant differences near the tank wall, tank bottom and tank cover as well as inside the tank wall. For such details the quantitative accuracy becomes too small. Therefore, a 3D-model has to be applied to investigate details in magnetic field strength and to design of shield assemblies

کلیدواژه ها:

power transformer ، magnetic field ، FEM-simulation ، transformer model