Redesign of standard, 24 slots, 2 pole, single-layer windings to combined YD-windings with higher efficiency
THE ADVANTAGES
Combined windings ( semi-six phase windings) have higher fundamental winding factors and produce smaller harmonic contents.
- The higher fundamental winding factor reduces the copper losses in the stator winding by using the same copper and iron mass.
- The smaller harmonic content reduces the torque ripple, the additional rotor losses and the magnetic noise. Furthermore, the starting torque rises up by asynchronous machines. Because of these benefits, the combined winding can be used in very high efficiency machines, in machines with a high power/size ratio or in highspeed drives.
Therefore, the efficiency can be increased without any additional active mass.
This 7-page publication includes an example of conversion from conventional, 24 slots, 2 pole windings to YD combined windings ( both options: serial & parallel connection, internal diagrams and winding data recalculation).