Computational efficient design framework for low AC loss, 3D printed windings

Winding AC loss can be substantial in power dense electrical machines due to their operation at fundamental frequencies approaching or exceeding 1 kHz. The use of multi-stranded transposed Litz conductors to mitigate AC loss effects can compromise achievable conductor slot fill and working current densities. Advances in metal additive layer manufacture allows for bespoke high fill, transposed windings to be printed, thus addressing the AC loss versus conductor slot fill trade. A computational efficient, hybrid analytical-numerical framework for the electromagnetic optimization of 3D printed rectangular transposed conductors is presented. The methodology is applied to a low loss hairpin winding design for a high-speed generator that, being devised for direct connection to a rectifier, has a phase current waveform with significant harmonic content.