On the Influence of Eccentricities on Flux Linkages of Permanent Magnet Synchronous Machines

The noise behavior of electrical machines is influenced by tolerances. Eccentricities in particular lead to poorer noise behavior. However, the measurement of NVH quantities is usually very complex. Therefore, it is of interest to be able to detect such tolerances also by other measurands. In this paper, the influence of eccentricities on the flux linkages is investigated. For this purpose, detailed investigations were carried out using FEA. In a further step, these are compared with the results obtained from a test rig measurement. Prior to this, a methodology is presented with which the angle-dependent flux linkages can be determined. It is shown that eccentricities cause only slight changes in the harmonic components of the flux linkages. Due to the symmetry properties of the investigated machine, the changes in the flux linkage caused by the different air gap lengths cancel each other out. This could also be confirmed in the experiment.