Figure 1.

Three anhysteretic curves ${\mu }_{\text{r}}(|\mathbf{H}|)$ used in this study. 1 (red): a generic curve given by equation (6a ) with $a_1=5/\pi \text{T}$, $a_2=5\times {10}^{-4}$ m A⁻¹. 2 (green): approximation of the M3 silicon steel datasheet of Arnold Magnetic Technologies™ at 2 kHz using equation (6b ) with $a_1=40$ m H⁻¹, $a_2=0.50$ T⁻¹. 3 (blue): Approximation of the METGLAS® 2605-SA1 foil core datasheet described by equation (6b ) with $a_1=80$ m H⁻¹, $a_2=0.82$ T⁻¹.