Investigation of the Forming Behavior of Copper Wires for the Compaction of Windings for Electric Machines

Abstract

To meet the increasing demand for highly efficient electric traction drives, the compact winding process has been developed at the wbk Institute of Production Science. One key element of the process chain is the compaction of the round wire stator windings. In order to enable an estimation of the sensitivities of the influencing factors, a simplified finite element simulation model was set up in the present work. In the calculations, the number of wire layers, the layer structure and the punch stroke were selected as factors with three levels each. The evaluation was performed by means of false color images and the maximum strains and stresses in the section plane of the slots.

Verifying Strand Transposition in Stator Windings via X-ray Computed Tomography derived Three-Dimensional Models

“…The adoption of power-dense electrical machines with excitation frequencies exceeding 1kHz for automotive and aerospace applications has led to increasing investigation into the variability present in AC losses within multistrand stator windings [1], [2]. While multistrand configurations are used to mitigate skin effect losses, proximity and bundle-level losses can be exacerbated due to the as-manufactured strand transposition, especially in random windings [3].…”