A comparison of 2D and 3D analysis methods for the prediction of cogging torque in an electrical machine having skewed slots

Two‐ and three‐dimensional computations of the cogging torque in a brushless dc motor are compared with measurements for both skewed and unskewed stators. The modeling of stator skew is considered both using a full three dimensional model with and without material anisotropy and using a set of displaced two‐dimensional slices. The errors inherent in the latter approach are discussed. A cost/benefit trade‐off between three‐dimensional and two‐dimensional analyses is considered.