Optimization of the MMF function of fractional slot concentrated windings

In this paper a novel method of determining optimal stator winding layouts for the permanent magnet with fractional slot concentrated winding machines is presented. This method based on a multiobject if genetic algorithm coupled to an analytical model of the MMF produced by the stator windings aims to reduce the harmonic content while maintaining a good winding factor for the working harmonic. The advantage of such an approach is that new degrees of freedom (irregular slot distribution, non-uniform distribution of the number of turns) likely to improve the distribution of the MMF waveform are taken into account. The example of application is given for two specific three phase windings; the first is characterized by a working harmonic of order five and the second by a working harmonic of order seven.