An approach estimating the number of domain walls and eddy current losses in grain-oriented 3% Si-Fe tape wound cores

A method is presented for estimating the number of domain walls in grain-oriented 3% Si-Fe tape wound cores under sinusoidal flux conditions by extending the method developed in a study of the dynamic behavior of 50% Ni-Fe square-loop cores. The results show that the number of domain walls increases approximately with exciting frequency as
f^{0.4 \sim 0.5}
. The calculated eddy current loss based on the modified Pry and Bean equation and the obtained number of domain walls agree well with the measured loss.