Iron Losses Due to Elliptically Polarized Magnetic Fields

Abstract

The iron losses occurring in an 11-mil cube-textured silicon-iron specimen, a 12-mil singly oriented silicon-iron specimen, and a 14-mil nonoriented silicon-iron specimen when subjected to a 60-cps elliptically polarized magnetic field (EPMF) are measured by means of a technique described previously and these EPMF losses are presented and compared. In general, the loss due to the EPMF was found to be equal to or less than the sum of the 60-cps alternating losses at the two induction levels that are the major and minor components of the EPMF. In the singly oriented and nonoriented silicon-iron specimens, a decrease in the losses for increasing flux densities for large elliptical fields is observed. The decrease continues until the eddy current loss becomes sufficiently large compared to the decrease in the rotational hysteresis loss to cause an increase in the total loss. This behavior was not found in the cube-textured specimen. An empirical expression, derived from the known pure alternating losses, is given which predicts the EPMF losses within 10% except at large EPMF's.