Improved Design of the Stator Windings of High-Power Induction Machines for Aerospace Applications

High-power electrical machines offer significant advantages, but only if their windings are properly designed. In such machines, where the supply frequency can reach up to 1000 Hz, the coils placed inside the stator slots are particularly susceptible to skin and proximity effects. The AC coil resistances can be significant, as they are directly proportional to the applied frequency, making the design of such machines a challenging task. This paper aims to contribute to a better understanding of the physical phenomena in high-power, high-frequency electrical machines. An analysis of the stator coil resistance at high frequencies is employed and an optimization technique addresses the minimization of the conductor losses, based on resistance calculations. Additionally, a simple mathematical method developed for AC resistance calculations is detailed. The numerical analysis validates the optimization results and lead to an improved design solution.