An Accuracy Enhancement of Parameters Calculation Of The Jiles-Atherton Model

Abstract

The features of the mathematical description of the hysteresis characteristics of electrical steels are considered, based on the idle experiment data and the Jiles-Atherton model. The analysis of the existing methods of Jiles-Atherton model parameters determination is carried out for the testing characteristics of magnetization. The testing of the transformer in single-phase magnetization mode was realized. The data of periodic oscillogram’s signals of phase currents and voltages are processed and represented by harmonic Fourier series for the magnetic flux density and magnetic field in the magnetic system. The set of their AC momentary values per one period conforming of the testing characteristic of the magnetization of electrical steel. To improve the accuracy of calculating these parameters, it is proposed the collocation points at specified times supplement to initial points of the hysteresis magnetization curve. For them, the momentary values of magnetic flux density and magnetic field should differ significantly from uniform ones. Optimality conditions are formulated for additional collocation points. The implementation of these conditions by the two-stage ordered elimination technique can significantly reduce the calculating time of the optimized parameters of the Jiles-Atherton model in comparison with the one-stage method with the same calculation accuracy. The use of optimized parameters reduces the error in calculating the area of the hysteresis characteristics of magnetization of electrical steel to 1.14%. Also allows to reduce the current and angular errors in calculating the idle currents of the power transformer to 4.17% and 3.85° for designing new or modernizing existing transformers.