Quasi-3D finite element modeling of a power transformer

A formulation based on 2D Cartesian and axisymmetric finite-element (FE) models, modified nodal analysis (MNA) and a multi-field system approach is proposed to analyze a three-phase power transformer. Interesting capabilities are thus achieved, overcoming the difficulties naturally arising with 3D simulations: high computational times and memory demand. A 2D Cartesian FE model is employed to represent the main cross section of the transformer. An axisymmetric representation is used for the end sections of each set of windings. All models are simultaneously solved, providing a powerful method that is easy to implement at low computational costs. We present preliminary simulation results that show that our proposal is sound.