Time-domain computation of rotational iron losses considering the bulk conductivity for PMSMs

This study investigates an advanced finite-element (FE) technique for the evaluation of rotational iron losses basedon a time-domain computation, where the bulk conductivity of the core materials is considered. The iron-loss characteristics arediscussed for a radial flux permanent magnet synchronous machine (PMSM) for a wind generation application, with closed slotsand outer rotor topology. The following factors are taken into account: (i) a real-time rotational iron-loss computation; (ii) the bulkconductivity of the steel laminations; and (iii) the influence of the controller harmonics on the system during transient conditions.The magnetic induction vector locus of each iron component is also discussed, where the magnetic induction is numericallymodelled [three-dimensional (3D) finite element analysis (FEA)], computed using multiple magnetic antennae and is alsoexperimentally verified. This comparative study shows a torque–frequency-loss computation that is presented from low to highfrequencies (50–800) Hz. The FE model of the total iron losses for the PMSM using both pure sinusoidal and proportional–integral pulse-width modulation currents is studied and experimentally verified on a surface-mounted PMSM. The proposedmethod of iron losses prediction significantly reduced the rate of error between 3D FEA and experimental data to 1.7%Peer Reviewe