Calculation of core losses under DC bias and harmonics based on Jiles-Atherton dynamic hysteresis model combined with finite element analysis

This paper presents a method to calculate the core losses in SiFe laminations under magnetizations with DC bias and harmonics. DC bias is usually generated by the ground return current of high voltage direct current (HVDC) system intrude into the windings of neutral-grounded transformers, which leads to increase of harmonics and core loss. For accurate calculation of core losses under DC bias, the Jiles-Atherton (J-A) dynamic hysteresis model is incorporated into the finite element method. The J-A dynamic hysteresis model is constructed by combining the traditional J-A hysteresis model with the models of instantaneous eddy current and excess losses. To account for the DC bias, the J-A dynamic model was modified by adjusting the parameters of instantaneous excess loss model. The theoretical results are verified by the measured results by a Single-Sheet Tester (SST 500).