New approaches for the applications of FEM in the routine design of power transformers using PC´s

Finite elements method (FEM) is becoming the standard tool for power transformers design and analysis [cf 1, 2]. This is due to the availability of numerous FE simulation packages which simulate the transformer fully including electrically, magnetically and thermally [cf 6] whereas present volume integral equations approach provides only a limited simulation of the transformer [1]. Two dimensional and three dimensional finite element modeling of power transformer have been used to analyze the leakage field, eddy current loss in the winding [2], the stray loss[3], the tank losses[4], and the eddy currents in core laminations[5],…. However, the direct application of FEM is faced by computational difficulties on presently available PCs. This is due to the very large amount of data and the associated numerical problems needed to model the details of three phase power transformers. This is required to compute the transformer deign parameters such as load losses, no load losses and short circuit reactance. This necessitates the use of large and expensive mini computers.