Analysis of Three-Phase Short-Circuit Electrodynamic Variation Characteristics of Power Transformers

When the transformer suffers from a short-circuit fault, the sudden short-circuit current will produce a huge short-circuit electric force, which may deform the windings and damage the insulation, especially the most serious three-phase symmetric short circuit of the double-winding transformer. It is of great value to study the electrodynamic variation characteristics of transformer winding short-circuit process, and then evaluate the short-circuit resistance of transformer winding. In this paper, ANSYS Maxwell finite element simulation software is used to establish a field-path coupling model. Through the external circuit, the three-phase short-circuit fault of the low-voltage winding is set at a certain time, and the electrodynamic variation characteristics under the impact short-circuit current are simulated and studied. The simulation results show that the influence of radial force on the winding is greater than that of axial force, especially on the intermediate phase B phase has the greatest influence.