Modeling of skew using the flux-MMF diagram [of PM machines]

The flux-MMF diagram has recently been used to predict torque ripple in different electric machine types. This paper describes a simple and elegant method, based on this technique, for predicting the effect of skew on torque ripple in permanent-magnet machines. Although it is well known that skewing minimizes torque ripple, the paper quantifies the difference in the extent of minimization between the electromagnetic torque ripple and the cogging torque