Abstract
DC biased magnetic properties of Fe-3 mass % Si powder cores have been measured and compared with calculated values using a nonmagnetic grain boundary (NMGB) model. Aluminum oxide fine powder was added into magnetic powder in order to change permeability and the amount of the powder was 0, 0.25, 0.4, 0.7, 1.0 mass %. DC initial B-H loops were measured and differential permeability was calculated at each magnetic force H. The values were compared with calculated one using the NMGB model which was taken account of gap width distribution. Best agreement of relative inaccuracy was additive amount 0.4 mass %. In that case relative inaccuracy of the powder core was from -0.4 % to 8.4 % with non gap distribution and from -3.00 to 4.00 % with gap distribution. The most improved case was additive amount 0 %. Relative inaccuracy was from -6.0 % to 22.8 % with non gap distribution and from -4.40 to 9.20 % with gap distribution.
