Calculation and analysis of mechanical properties of transformer windings accounting for actual operating characteristics

The mechanical stability of power transformer windings under short-circuit impact constitutes a core safety requirement for the equipment. Traditional spring-mass models suffer from insufficient computational accuracy due to limitations in equivalent stiffness coefficients, making it difficult to accurately predict winding displacement responses. This study presents an in-depth investigation on a 110 kV power transformer. First, the spatial distribution of the transformer’s leakage magnetic field was precisely and rapidly calculated using the method of images. Elastic modulus curves were measured under various operating temperatures, enabling a modification of the traditional spring-mass model. Based on these curves and the modified model, a calculation method for electromagnetic forces and displacements of transformer windings, accounting for actual operating environments, was proposed. Subsequently, electromagnetic-structural force field simulations of the 110 kV power transformer were conducted, yielding distributions of leakage flux, electromagnetic forces, and the resulting displacements. Finally, short-circuit tests were performed on the 110 kV power transformer. The proposed method, finite element method results, and experimental data were compared, validating the accuracy of the proposed approach.