Investigation on AC Losses in the End Conductors of Additively Manufactured Hairpin Windings

Hairpin windings (HWs) have recently been one of the most adopted solutions to enhance torque and power density of electrical machines (EMs) in automotive applications. However, they are typically characterized by high AC losses at high-frequency operation. While several research works have focused on how to model and reduce these losses within the active parts of HWs, only a few studies on their impact in the end winding (EW) regions are available, and mainly for classical HWs featuring constant cross section. This work investigates the AC losses occurring in the EWs of a traction motor with an asymmetrical HW printed with additive manufacturing (AM). The analyses are carried out through 3D finite element (FE) simulations over a wide frequency range. The losses in the EWs are determined for both copper and AlSi10Mg conductors. Comparative considerations are finally drawn, with the aim to providing general guidelines on how to model and print the EWs of asymmetrical HWs.