Why state-of-the-art analytical models for eddy current losses in PM of PMSM are insufficient for variable speed motors

Abstract

This is the third paper in a series on novel methods for calculating eddy current losses in permanent magnets (PM) and the shortcomings of previously conducted analyses. In the first paper, Ruoho’s work on homogeneous materials was discussed. The distribution of fields has been expanded to include the reaction field of the eddy currents within the permanent magnets. This approach was based on the methods of the harmonic complex AC calculation. In the second paper, the models were expanded to enable a harmonic calculation of eddy current losses in permanent magnets for homogeneous fields including the effects of eddy current losses in an adjacent ferromagnetic material, leakage flux factors, and source behavior. In this third and final publication, a look at state-of-the-art analytical models will be taken. With regard to the results of the second publication of this series, it can be shown that established analytical models are insufficient when calculating inverter-related eddy current losses in permanent magnets of permanent magnet synchronous machines (PMSM). Furthermore, a short introduction to eddy current loss mechanics in permanent magnets of PMSM will be given.