Influence of Winding Scheme on the Iron-Loss Distribution in Permanent Magnet Synchronous Machines

The influence of the winding scheme [concentrated, single-tooth, distributed (pitched, unpitched)] on the iron-loss distribution in a rotor and stator is to a large extent unknown. At present, windings are primarily selected with respect to back-EMF harmonics and torque fluctuation. In such approaches, the influence of iron losses is disregarded. Moreover, minor loop losses are not covered by most iron-loss models and are therefore ignored. This yields inaccurate results. In particular, for interior permanent magnet machines, the rotor temperature has to be taken into account. For variable-speed drives, losses have to be calculated over the complete operating range. Hence their distribution is studied in this paper for various operating points. The influence of the winding scheme on iron losses and iron-loss distribution is investigated based on finite-element simulations.