Study of magnetic losses in Mn-Zn ferrites under biased and asymmetric excitation waveforms

We present magnetic loss measurements performed on Mn-Zn ferrite samples using an original experimental setup recently developed and described elsewhere \cite{Loyau2009-1}. Measurements have been performed on small amplitude loops ($100$ mT peak to peak induction amplitude) under excitation frequencies ranging from $20$ kHz up to $200$ kHz. Loss characteristic is explored under non conventional excitation reproducing typical working conditions of power electronics integrated devices. We present measurements performed under triangular symmetric and biased excitations with offset field in the interval: $0\leq H_{off} \leq 110$ Am$^{-1}$. A second set of measurements has been performed under triangular asymmetric excitation where the field change rate was different between the ascending and the descending branch of the cycle. gular asymmetric excitation where the field change rate was different between the ascending and the descending branch of the cycle.