I. Introduction
For computer-aided design (CAD) of magnetic power de-vices, including electric machines, transformers, inductors, and other static reactors, all accurate prediction of loss in magnetic materials is essential. A widely used calculation is a power law equation [1], [2] \overline{P_{c}.(t)}=kf^{\alpha }\hat{B}^{3}\eqno{\hbox{(1)}}
where is the peak flux amplitude, is the time-average power loss per unit volume, and is the frequency of sinu-soidal excitation, and , and are constants found by curve fitting. A similar equation. but without the frequency depen-dence, was proposed by Steinmetz in 1892 [3]. and so (1) is often referred to as the Steinmetz equation. Unfortunately the Steinmetz equation, as well as the data provided by manufacturers of magnetic materials, is based only on sinusoidal excitation, whereas switching power converters and, increasingly electric machines, can have very different waveforms. These nonsinusoidal waveforms result in different losses [4], [5], [6]. DC bias can also significantly affect loss [7], [8], [9], A better method of determining loss accurate for a wider variety of waveforms is needed. Our work is motivated primarily by applications to MnZn power ferrite materials. However, the results may be useful for other materials as well