An Improved Jiles-Atherton Model for DC Bias of Transformer

The Jiles-Atherton (J-A) theory is widely used in the field of semi-macro hysteresis modeling. However, the DC bias transformer model based on presented J-A theory has a big deviation due to only existence of AC component and the description of the hysteresis curve is incomplete in the biased state. Firstly, this article makes a revision to the J-A formula under normal excitation state. Moreover, through innovative introduction of DC component to improve non-hysteresis magnetization curve and differential expression of magnetization of J-A theory under DC bias state, and the pinning coefficient k is modified to establish a numerical simulation model. By verfied, the improved J-A model can describe the magnetization characteristics of ferromagnetic materials in the biased state better. Then, based on the improved J-A formula proposed a transformer DC bias iterative model. Finally, a transformer in a 500 kV grid is used to verify the accuracy of transformer DC bias model based on the improved J-A formula.