Investigation of Transformer Electromagnetic Forces Caused by External Faults Using FEM

This paper is focused on the investigation of transformers internal electromagnetic forces caused by external fault. The simulations are based on the finite elements method (FEM) to model a three-phase transformer and also to calculate the forces via traditional mechanical and electrical equations. Normal operation and symmetrical fault conditions are used for the estimation of internal radial and axial forces. This work, which leads to specific transformer performances, allows to verify the potentiality of the method used and also the physical consistence of the computational simulations. The results shown in this paper are flux distribution, losses and other information regarding the equipment operation. The FEM approach has shown to be a powerful tool on the estimation of mechanical stress within transformers and it can be quite useful at the design stage of such devices