In Emetor, a winding is called concentrated winding when the number of slots per pole per phase is fractional and strictly lower than 1.
The coils of fractional-slot concentrated windings are concentrated around the teeth, i.e. non-overlapping. Traditionally, however, "concentrated windings" refers to windings having one slot per pole per phase.
In the Emetor winding calculator, green cells indicate concentrated windings.
The number of layers in every slot can be either one or two. However, single-layer windings which have coils wound only on alternate teeth, are only feasible when the number of slots is a multiple of 6. For double-layer windings, each tooth carries one coil and the slot is usually divided vertically. Below, you can see the example of layouts of a 10-pole 12-slot single-layer, respectively double-layer concentrated winding:
Fig. 1 Single-layer 10-pole 12-slot concentrated winding with a winding factor of 0.966.
Fig. 2 Double-layer 10-pole 12-slot concentrated winding with a winding factor of 0.933.
Read about another glossary term