Simulation and Analysis of Power Transformer Winding Vibration and Deformation under External Short-circuit Faults

The transformer winding deformation and the insulation damage will occur under the impact of huge electromagnetic forces caused by the short circuit faults. In this paper, the electromagnetic-mechanical (E-M) field coupling 3D FE model was used for analyzing the transient characteristics of power transformer under short circuit faults. Considering the process of the transformer winding suffering short circuit current is a complicated multi-field coupling problem, this paper explores the inter-relationship between the short circuit fault topology, electromagnetic field and the mechanical field. Both the mathematical model of each field involved and the E-M field coupling model have been built. By the use of 3D FEM, the transient characteristics such as the electromagnetic forces, stress distribution and displacement of the transformer model have been calculated and simulated. Additionally, by analyzing the results from the simulation example, the radial and axial forces characteristics and the structure design suggestion for the winding have been obtained and proposed.