Comparison of Methods to Calculate Iron Losses Caused by Harmonic Fields in Rotating Machines

In this paper, we examine the accuracy of several calculation methods for iron loss of rotating machines using the finite element method. Two calculation methods are compared with the measurements. One is based on the Fourier transformation of the flux density waveforms at each finite element. The other is the direct calculation from the waveforms without Fourier transformation. It is clarified that the errors of the calculation methods vary due to the kinds of machines and that the method based on the Fourier transformation overestimate the hysteresis loss in case of highly saturated machines.