Multi-step approach for fast calculation of magnetic field in power transformer yoke shunt

The multi-step approach for the calculation of magnetic field in a power transformer yoke shunt is proposed in the paper. This approach can be used as an alternative to the time-consuming 3D FEM modelling when a fast calculation is needed - e.g. optimization of transformer geometry during the design process. A single 2D FEM model can not be used for the calculation of the magnetic field in the yoke shunt. Therefore, the magnetic field is calculated in steps, using multiple 2D FEM models. The proposed approach is tested on two examples of real power transformer geometries. The validity of the approach is verified using the results of the 3D FEM calculations. In the worst case, the maximum value of the magnetic flux density, calculated using the proposed multistep approach, deviates by 6% from 3D FEM. The main advantage of the proposed approach is significantly reduced computation time from several hours for 3D FEM to less than a minute for the proposed approach.