3D finite element computation of the high frequency parameters of power transformer windings

A computation of power transformer parameters with a numerical method using finite elements is presented. The modeling, based on the calculation of the 3-D electromagnetic field, allows a novel approach to the study of the high-frequency phenomena that propagate along the transformer windings. These parameters include the inductive and capacitive parts of a discretized winding. The energy method is used for finding the inductive parameters. The capacitive matrix is obtained using a method based on the computation of the charge on each disk winding. These methods are very efficient compared with analytical and 2-D numerical techniques: they allow the exact computation of the discretized winding parameters for any complex 3-D geometry. Examples of calculated parameters are given. An objective is to establish a computational model to study the propagation of step front surges along transformer windings.>