This paper presents a numerical method for the investigations of the mechanical effects of the worst-case faults with three-phase short circuit in a power transformer. In order to balance the calculation time with accuracy, the high-voltage and low-voltage windings are modeled into 21 and 17 disks and there are 12 spacers between the adjacent disks. By the use of the 3D FEM, the axial, radial and cumulative electromagnetic forces acting on each disk have been computed. From the simulation results, the method provides representative results and is useful for windings damage analysis and structural design in other types of transformers instead of dangerous and costly tests.

Power transformer,short-circuit faults,winding vibration and deformation,FEM