Manufacturing influence on the magnetic properties and iron losses in cobalt-iron stator cores for electrical machines

Abstract

The manufacturing influence on the magnetic properties and iron losses in stator cores made of cobalt-iron is investigated in this study, with a focus on the annealing and stacking process. Hysteresis and iron loss curves from measurements as well as a microscopic structure analysis are presented. FEM simulations are used to investigate the fringing effect in the stator cores due to the stator slots and others geometrical effects. A correction factor is derived and applied to the measurements. Furthermore, it is shown, that for cobalt-iron lamination sheets, the annealing process with an exact temperature and duration is absolutely essential to achieve expected magnetic and mechanical properties in the material.