Variations in Excess Losses in Thin FeSi Sheets Due to the Cutting Process

The article discusses the influence of mechanical and laser cutting on changes in excess losses occurring in low-loss FeSi laminates used to build the cores of energy-saving electric motors. Material characterization tests have been carried out on rectangular strips of different width spanning in the range from 4 mm to 60 mm. The analysis was on the results of measurements and approximations of the curves through suitable mathematical models. The result was the determination of changes in the coefficients defining the excess loss component, proposed by Bertotti many years ago. In this perspective, the scope of applicability of the formula defining this component of iron loss is also discussed.