I think that, to some extent, I already answered this question for you but here again are the parts relevant to this particular question:
Fractional pitching reduces harmonics in the airgap field (it's usually aimed at reducing the 5th and 7th) and in turn reduces parasitic losses in the windings and core and gives a better output voltage waveform.
The use of fractional pitching also results in a slight reduction of the voltage induced per turn but so long as the short pitch fraction is kept reasonably high (around 0.8 is normally used), this is not significant compared to the advantages gained in harmonic reduction.
In another answer to you concerning the distribution factor, I discuss the need to reduce voltage waveform harmonics. These considerations apply equally here.
Please take a moment to award one of your answers "Best Answer". That's partly why we do this!
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I think that, to some extent, I already answered this question for you but here again are the parts relevant to this particular question:
Fractional pitching reduces harmonics in the airgap field (it's usually aimed at reducing the 5th and 7th) and in turn reduces parasitic losses in the windings and core and gives a better output voltage waveform.
The use of fractional pitching also results in a slight reduction of the voltage induced per turn but so long as the short pitch fraction is kept reasonably high (around 0.8 is normally used), this is not significant compared to the advantages gained in harmonic reduction.
In another answer to you concerning the distribution factor, I discuss the need to reduce voltage waveform harmonics. These considerations apply equally here.
Please take a moment to award one of your answers "Best Answer". That's partly why we do this!