EUROPEAN INTERCOMPARISON OF MEASUREMENTS OF ROTATIONAL POWER LOSS IN ELECTRICAL SHEET STEEL

This paper presents the results of a European intercomparison of measu rements of the magnetic properties, mainly the power loss, of electric al sheet steel under the conditions of rotating and alternating flux. In the latter case, different directions of the flux in the sample's p lane were considered. Two grades of grain-oriented and six grades of n on-oriented material were included in the exercise. The six participat ing laboratories applied different, but partly similar, measurement me thods. With non-oriented (NO) materials, the results are in fairly goo d agreement. For grain-oriented materials the results differ considera bly. This can be explained by the large fluctuations of the differenti al phase angle due to anisotropy, a small measurement area of the samp le compared with grain size, and incomplete flux-vector control. The s ituation appears to require further investigations before a standard c an be defined.