A NEW FITTING METHOD FOR HYSTERESIS LOOP OF TRANSFORMER BASED ON FRACTAL THEORY
LI Gui-cun · Power System Technology · 2003
Accurately simulating the dynamic magnetizing processes of the ferromagnetic materials used in transformers and mastering the dynamic magnetizing law of the materials are the key factors to improve the transient simulation accuracy of transformers. Applying the basic viewpoint in fractal theory, it is proved that the hysteresis loop family of ferromagnetic materials is a kind of fractal figure, the law which is obeyed in the dynamic magnetizing processes of ferromagnetic materials is revealed in essence. The relation between the major and minor hysteresis loops of transformer is researched. Based on the basic theory of iteration function system in fractal theory, a new method of variable compressed factor is put forward, in which the linear variable compression factor is used in the iteration calculation of the major hysteresis loop, for the fitting of minor hysteresis loop of ferromagnetic materials. The correctness of the presented method is verified by the simulation results.