Investigating electromagnetic forces in multi-winding transformers: A numerical analysis

• A numerical investigation assesses the impact of multi-winding configurations on transformer electromagnetic forces. • Finite element models analyze forces under three different conditions for comprehensive results. • Short-circuit tests validate the accuracy of the finite element method findings. • Research insights will optimize transformer and converter design, ensuring reliable performance and operation. This paper presents a numerical study on the impact of multi-winding configurations on radial and axial electromagnetic forces in multi-winding transformers under three different conditions. Finite element analysis (FEA) models are used to simulate three scenarios: (1) applying rated current to the upper winding, (2) applying rated current to the lower winding, and (3) applying rated current to all windings simultaneously. The results show a significant difference: when applying the rated current to an upper or lower winding in the first and second conditions, the axial and radial forces are lower than when applying the rated current to all windings. The analysis demonstrates that when the rated current is applied to all windings of the multi-winding transformer, the resulting radial and axial electromagnetic forces are more evenly distributed. Prototype short-circuit tests validate the accuracy of the finite element method results. This research sheds light on the behavior of multi-winding transformers under different conditions, offering valuable insights into their design and operation. This work will assist converter and multi-winding transformer designers in optimizing their designs and ensuring reliable performance.