Relationship among eddy current loss, frequency, maximum flux density and a new parameter concerning the number of domain walls in polycrystalline and amorphous soft magnetic materials

A new approach is presented for understanding the frequency and flux density dependence of eddy current losses in polycrystalline and amorphous soft magnetic materials by introducing an experimentally derived parameter which is thought to be proportional to the number of active domain walls. The relationship among eddy current loss, frequency, flux density and the new parameter is described by simple formulas and the result derived from these formulas agrees well with the Pry and Bean equation qualitatively and will offer an effective way to appreciate the mechanism governing eddy current loss.