Rotational power losses and vector loci under controlled high flux density and magnetic field in electrical steel sheets

This paper presents the rotational power loss P, curves measured for nonoriented, conventional grain-oriented and high-permeability grain-oriented electrical steel under controlled loci of flux density B, or magnetic field H. The P is measured at 10, 50, and 250 Hz with the radius of circular loci of B being controlled from 0.5 to 2.0 T and the radius of circular loci of I-I from 50 to 20 kA/m. The well-known phenomenon of decreasing P at higher magnetization is confirmed in the results. The maximum P under controlled circular H can be up to 2.5 times higher than under controlled circular B and up to six times higher than the value of alternating loss for anisotropic electrical steels. In thicker laminations at higher frequencies, the peaks in P curves vanish due to increased contribution of eddy currents.