Systematic error of analytical iron loss approaches in electrical machines

The proper calculation of iron losses is still a challenge for designers of rotating electrical machines. There are a lot of analytical approaches to calculate the losses in order to reach good results. The loss coefficients of the approaches strongly depend on the operating range of the magnetic flux densities and frequencies. Comparisons between the analytical approaches and measurements of the specific iron losses of unmachined electrical sheets confirm this assumption. For this purpose several methods of calculating the iron losses in the band of high magnetic flux densities and in a great range of operating frequencies are discussed. The approaches of the losses for unmachined electrical sheets are rated. The magnetic circuit of machines is analytically calculated in order to apply the approaches to electrical machines. As a result the effect of the systematic error of the different iron loss approaches to electrical machines is analyzed and evaluated.