Vector Hysteresis Modeling Coupled with a Loop-based Magnetic Equivalent Circuit

Abstract

This paper proposes a method to include the anisotropic magnetic hysteresis property of the soft-magnetic material in the magnetic equivalent circuit (MEC) modeling. The loop-based MEC formulation is improved to handle the non-linearity of the anisotropic magnetic hysteresis. Single MEC element of NO27 electrical steel is modeled in 2-D under both rotating and alternating magnetic fields to achieve an accurate iron loss estimation for different excitation frequencies. The developed model is coupled with both the single-valued BH curve (SVC) and the hysteresis BH loop (HL) of the non-linear magnetic material. The magnetic flux density is calculated as the output of the model and used for the comparison of both magnetic saturation calculations. The results show that an alternating magnetic field in a single direction with a peak value smaller than 300 A/m causes a discrepancy of more than 10% between HL and SVC, where the knee point of the SVC is located at 200 A/m. Although the SVC approximation gives realistic results under the deep magnetic saturation, it is not capable of estimating the iron loss accurately. The proposed model with the HL calculates the core loss density as 4 and 28 W/kg for 1000 A/m peak value with 50 and 200 Hz alternating magnetic field excitation, respectively.