Core loss prediction using magnetic circuit model for fractional-slot concentrated-winding interior permanent magnet machines

This paper presents a promising technique for estimating the cores losses of a fractional-slot concentrated-winding (FSCW) interior permanent magnet (IPM) machine using a simplified lumped-parameter magnetic circuit model (MCM). This model incorporates several key nonlinear phenomena including (i) magnetic saturation; (ii) cross-saturation effects between the d- and q-axes affecting both flux linkages and inductances; (iii) stator slotting effects; and (iv) localized effects due to rotor bridges. The MCM is configured to predict the flux densities waveforms in the iron as the rotor rotates. Fourier transformation is then applied to extract the frequency components of the flux density in each iron core permeance element, followed by estimation of the losses in each element. These permeance losses can then be combined to provide the estimated iron losses in the total core. Very good agreement is demonstrated between core loss predictions delivered by this model for a target FSCW-IPM machine and those provided by finite element (FE) analysis.