Rotational power loss of silicon steel sheet

Rotational power losses have been measured on nonoriented grain-oriented silicon steel sheets under different rotational flux conditions. Several methods have been proposed for this purpose. Among these, a method based on the measurement of the field quantities B _x, B_y, H_x, and H_y seems to be the most convenient as far as the preparation of the test specimen is concerned. In this method, the rotational power loss P_r is measured as the torque loss generated from the angle of lag between the H-vector and the B-vector caused by the rotating field. The effect of the axis ratio of the rotational flux components and of the inclination angle of field strength relative to the rolling direction of a sample sheet on the rotational power loss was investigated with the method. This loss was compared with the conventional loss, which was shown as the sum of loss P_t in the x and y directions. Although in the nonoriented steel sheet P_t (conventional rotational loss) is larger than P_r , in the grain-oriented steel sheet P_t is smaller than P_r. When the field strength was applied in the nonoriented sheet at a 45° angle from the rolling direction of the sheet, the rotational power loss reached minimum values