Accurate – Axis Modeling of Synchronous Machines With Skew Accounting for Saturation

This paper exemplifies the influence of skew on the magnetic behavior (i.e., flux linkages and inductances) and torque characteristic of a synchronous machine. Thereby, it proposes a computationally efficient semianalytical technique to accurately derive the parameter model of a synchronous machine incorporating skew, whilst considering the effect of saturation and d-q axis cross coupling. The proposed technique uses only one set of 2-D finite element (FE)-computed data corresponding to the unskewed machine, and can be applied for the prediction of either average or instantaneous d-q axis flux linkage and torque of any synchronous machine with an n number of skew slices and any skew angle. The validity of the technique is verified by FE analysis and measurements obtained from a prototype permanent magnet assisted synchronous reluctance machine developed for a traction application.