Significance of Vector Hysteresis Modeling in the Analysis of Variable Flux Reluctance Machines

This article presents the magnetostatic analysis of a 12/10 variable flux reluctance machine where the nonlinear magnetic characteristics of the soft-magnetic material are modeled using two different techniques: the single-valued magnetization curve and Jiles-Atherton vector hysteresis modeling. The root mean square and the peak local errors in the magnetic flux density calculated by the single-valued curve are found to be 0.23 T and 0.5 T, respectively. Moreover, the calculated torque under magnetic saturation with a single-valued curve exhibits over 5% error when compared to the Jiles-Atherton model, as it only models uni-directional material characteristics. Lastly, the modeled hysteresis loss of the applied two techniques is compared. The discrepancy between the two models is found to be 25% in magnetic saturation and reaches 48% for large dc-to ac-field excitation ratios in the linear region.