Performance evaluation of permanent magnet synchronous machines with concentrated and distributed windings including the effect of field-weakening

The aim of this paper is to evaluate different concentrated fractional pitch winding designs in comparison to a distributed full pitch winding design with one slot per pole per phase as a reference. The rotor design is fixed and the permanent magnets are surface mounted, i.e. the rotor has negligible magnetic saliency. The studied parameters are power capability considering inverter capacity, field-weakening performance, torque ripple (including cogging), iron losses, winding losses and thermal behaviour. The results of the machine performance comparisons are based on a comprehensive use of finite element analysis tools. Measurement results from tests on a laboratory prototype are used to define heat coefficients.