Electromagnetic Properties Determination Of Electrical Steels

The problems improving the accuracy of numerical calculations of the transient hysteresis characteristics of electrical steels for power transformers are studied in the work. A harmonic analysis of time dependence of the magnetic field intensity in the steel flat of the ferromagnetic material is performed according to the experimental data by Epstein apparatus. It is proved, that the amplitude of the first harmonic component of the magnetic field intensity does not exceed 64% at magnetic flux density of more than 1.0 T. A new approach for transient characteristics of magnetizing is proposed to increase the accuracy of the mathematical description of the Jiles-Atherton hysteresis model with help experimental data. For these characteristics, the Jiles-Atherton model is supplemented by the condition based on the equality of the simulated specific hysteresis losses and the coercive force proportionality parameter. Using the modified Jiles-Atherton model to simulate the electromagnetic field of the Epstein frame in the Comsol Multiphysics software provides the current error reduction to 1,114%. It corresponds to the accuracy requirements for designing new types of power transformers.