Parameter analysis of an IPM machine with fractional-slot concentrated windings, part I: Open-circuit analysis

The application of concentrated windings in permanent magnet machines significantly reduces overall machine length, due to the elimination of end winding overlap making it more suitable for areas with space limitations. Efficiency is also increased due to the reduction of copper loss. In order to take full advantage of these benefits, optimization strategies have been implemented and its effects are studied with the use of finite element analysis using FLUX2D. In this paper, open-circuit analysis is performed on three different winding configurations with constraint of having the same 14-pole rotor. Resultant emf waveforms and cogging torque waveforms produced by the three winding types are also illustrated in this paper.