This page talks about the winding Factor variations with pole-slot combinations.
The winding factor is representative of the magnitude of resulting stator magnetic field and hence the torque that a given machine design configuration offers. Harmonics in the winding factor are also indicative of the harmonics in the torque waveforms and phase/line voltage waveforms.
I created a script in scilab that calculates the winding factor as a product of pitch factor and distribution factor. I set the skew factor to 1.
The BLDC type of winding has typically concentrated winding with single throw of coil, alternatively called tooth winding, or singhe-throw winding. The distributed winding, also called multi-throw winding is a typical configuration of IPM and IM topologies.
It turns out that if we ignore the unbalanced winding configurations of few pole-slot combinations, the winding factor follows certain trend, as indicated by the below figures.
Both the Single throw and multi throw winding factor plots are represented next to each other, for better comparison.
I am yet to include 1-layer winding wherever possible.
I am looking forward to creating similar plots for higher phase systems.
WindingFactor_mini
WindingFactor
The following image indicates the cogging periodicities
The following image indicates the number of winding symmetries
