COUPLING 2D FINITE ELEMENT MODELS AND CIRCUIT EQUATIONS USING A BOTTOM-UP METHODOLOGY

Abstract

The aim of this paper is to present an approach, able to deal with all possible connections of voltage and current sources and impedances, combining conductors in which the skin effect is taken into account and conductors in which skin effect is neglected. This approach is obtained using a bottom-up methodology. In this way, the meaning of terms in the generalized approach is naturally inherited from some specific problems. This model is presented in a compact form, preserving sparse, symmetric and positive-definiteness matrices. The vectors and matrices, computed during the solution stage, are employed in engineering calculations as current and inductance computations providing compact expressions suitable for efficient algorithms. Finally, the proposed approach, implemented in a FEM software package developed by the authors, is applied to the study of a three-phase transformer, supplied with a balanced three-phase voltage (sinusoidal and nonsinusoidal) and loaded with an unbalanced three-phase RL impedance. The agreement between the computed and experimental results shows the validity of the proposed model and its implementation.