In the paper, the mathematical model of coupled electromagnetic and thermal phenomena in the pulse transformer taking into account the magnetic hysteresis is presented. For the mapping of magnetic hysteresis, Jiles-Atherton model is applied. In order to solve field equations, the finite element method (FEM), "step-by-step" procedure and Newton-Raphson algorithm are used. Software elaborated on this basis is used for analysis of hysteresis loss in the core. Selected results of investigations are shown.

In the paper an algorithm and computer code for the identification of the hysteresis parameters of the Jiles-Atherton model have been presented. For the identification the particle swarm optimization method (PSO) has been applied. In the optimization procedure five design variables has been assumed. The computer code has been elaborated using Delphi environment. Three types of material have been examined. The results of optimization have been compared to experimental ones. Selected results of the calculation for different material are presented and discussed.