A computer model for surge distribution studies in transformer windings

In this work, a computer model for calculating surge distribution in power transformer windings is presented. The model is based on multiconductor transmission line theory, considering each disk coil as the basic element for the analysis. The electric parameters R, L, C and G are calculated by using conventional formulations. The electrical parameters are used for calculating modal parameters in order to represent the winding as a two port network. The transformer model is validated by means of a comparison between measured and calculated transient voltages in a phase winding with 34 coil disks, in a scaled down prototype of a power transformer.