EDDY-CURRENT LOSSES IN MAGNETIC SHEET WITH SIMPLE BAR-LIKE 180-DEGREES DOMAIN-STRUCTURES

The eddy current losses in thin magnetic sheets have finite width (W), thickness (d) and simple bar-like domain structures are calculated numerically assuming sinusoidal time variation of flux and uniform domain wall speeds. The Pry and Bean values for the ratio of calculated eddy current loss (P e) to its classical value (Pc) are attained for fixed domain width (2L) in the limit W→∞. For a fixed number of domains (N) it is found that Pe/Pc has essentially the Pry and Bean value for 2L/d≳2 if N is odd (half-size end domains). With decreasing domain width, Pe/Pc decreases monotonically and, for fixed N (odd or even), tends to zero as 2L/d→0.