LOSS SEPARATION UNDER ELLIPTICALLY ROTATING B-FIELD WITH BIAS FIELD IN ELECTRICAL STEEL

Measurements of the properties of electrical steel sheet under two-dim ensional excitation with a bias field, with special emphasis on loss s eparation into alternating and rotational losses, are reported. The ap plied dc field is small compared to the field necessary to saturate th e sample, ensuring that the measurements are performed under sinusoida l ac flux conditions. Non-oriented steels always show an increase of t he loss with increasing dc field independently of the direction of the dc field. Grain-oriented samples have a different behaviour if the dc field is applied perpendicular to the rolling direction, showing a mi nimum of the total loss in a special range of the dc field. The separa tion of alternating and rotational losses is influenced by the dc fiel d if the averaged loss angle changes.