Skew interface conditions in 2-D finite-element machine models

In two-dimensional finite-element machine models, the skewing of the stator or the rotor is commonly taken into account by considering several cross sections at different axial positions, assembled by electrical circuit relations. Since the problem size scales with the number of slices, the computational cost rises significantly. In this paper, skew is modeled more accurately and more conveniently by imposing spectral interface conditions incorporating skew factors at a circle or an arc in the air gap.