Geometrical and electrical optimization of stator slots in electrical machines with combined wye-delta winding

Novel fractional slots tooth concentrated windings often consist of several winding systems. This structure allows creating good MMF distributions with low space harmonic contents. A good example is the combined wye-delta winding. Methods presented in this paper allow additional optimization steps in already designed electric machines containing the combined wye-delta winding even with fixed number of turns and fixed machine geometry: - Minimization of the ohmic resistance - Saving of conductor material without any negative impact on the machine behavior - Improvement or even optimization of the heat distribution over the circumference of the machine supporting the cooling system.