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

To minimise AC losses in power dense electrical machines, multistrand stator windings are routinely employed. However, the magnitude of AC losses can be highly sensitive to the strand transposition achieved in the as-manufactured winding, which can differ significantly from that assumed during design. This paper employs X-ray Computed Tomography (XCT) to verify the twisted strand transposition in a compressed aluminium coil, through the construction of 3D models for each of the strands within the coil. These models enable the strand transposition to be verified by qualitative and quantitative means, providing initial insight into the actual strand transposition achieved at the mid-point of the coil active length.