Semi-Analytical Calculation of PM Eddy Current Loss in IPMSM Using Equivalent Magnetic Circuit Model

A semi-analytical method is proposed for rapidly calculating the eddy current loss in permanent magnets (PMs) of interior permanent magnet synchronous machines (IPMSMs), incorporating the effects of current harmonics and PM segmentation. The eddy current reaction field is solved with the equivalent magnetic circuit model extracted from finite element (FE) analysis. The internal and external equivalent magnetic circuits of the PM are established respectively, with their parameters determined with FE sweeping and interpolation. The novelty of this work lies in fully considering the eddy current reaction effects, especially the interactions between the eddy current reaction fields in different PMs. The accuracy of the proposed method is validated through FE simulations of a 9-slot 6-pole IPMSM, demonstrating higher computational efficiency than the conventional FE method and higher accuracy than the existing semi-analytical methods. Furthermore, the proposed method is applicable to various winding and rotor configurations.