Effect of Laser Cut on the Performance of Permanent Magnet Assisted Synchronous Reluctance Machines

This paper investigates the effect of laser cutting the stator lamination on the performance of a permanent magnet assisted synchronous reluctance machine (PMA SynRM). A technique for the modeling of the B-H curves of electrical steel laminations is described. It considers the extent of degradation of the magnetic properties caused by laser cutting, reported in the literature, and assumes that the degree of damage is determined by the distance between the cut edges or the width of the strip. The technique is employed to predict the performance of the PMA SynRM, which exhibited significant discrepancies between measured and predicted performance assuming the ideal manufacturer's B-H curve. In the analysis, the machine is subdivided into regions characterized by the distance between the edges, and each region is assigned a corresponding B-H curve. Through comparisons between experimental measurements and predictions, this paper highlights the potential impact of laser cutting on the performance of electrical machines, especially those exhibiting a large cutting length per steel area. Therefore, it demonstrates the necessity of incorporating such effects into the modeling in order to improve the prediction accuracy.