Equivalent network model for magnetic field and circuital analysis of transformers including hysteresis effects

In this paper, an equivalent network model for transformer analysis including hysteretic effects is presented. The nonlinear electromagnetic problem is reduced to the analysis of an equivalent network by integrating Ohm's law inside every elementary volume into which the solid bodies of the examined system are subdivided. The model allows the analysis of the electromagnetic field distribution for the evaluation of local saturation effects by using fine discretizations. Furthermore it gives a simple and efficient equivalent circuit of the transformer for external effects determination by using coarse discretizations. Hysteresis effects in the steady state case can be taken into account by an equivalent hysteretic loop obtained from standard measurements. The method has been tested by comparison with experimental data.