Hairpin Windings Manufacturing, Design, and AC Losses Analysis Approaches for Electric Vehicle Motors

This paper investigates the hairpin winding configuration as a solution to increase the power density of electric vehicle motors by enhancing the slot filling factor. Moreover, the paper presents various manufacturing techniques of this winding and describes it in detail. Further, it provides a novel additive manufacturing method as an alternative option for conventional production methods to mitigate AC losses using flat rectangular conductors in hairpin winding rods. Following the proper connection of conductors in parallel paths is considered, and the essential rules for this purpose are described. Finally, the analytical and numerical approaches for calculating AC copper losses and the AC loss factor are presented in detail.