Accurate \(d\) –\({q}\) Axis Modeling of Synchronous Machines With Skew Accounting for Saturation

Abstract

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.