Evaluation of the interdependency of mechanical cutting and magnetic anisotropy on the magnetic properties of FeSi electrical steel

摘要

Due to present-day challenges for the improvement of the operating characteristics of rotating electrical machines, the core material is regarded as increasingly important. Non-oriented (NO) electrical steel sheets are conventionally used for the construction of magnetic cores of rotating electrical machines. The most appropriate choice of material and machine design is based on standardized material data obtained from Epstein frames or single sheet testers. Both, low losses as well as good magnetizability in any spatial direction of the sheet plane are requested. Despite their name, NO electrical steels do show a magnetic anisotropy. A significant increase of loss and decrease of permeability can additionally be induced by mechanical cutting processes to shape the magnetic circuit. Magnetic anisotropy and induced mechanical stress can affect the local iron-loss distribution, magnetizability, acoustic behavior and therefore, have to be considered in numerical simulations of electrical machines. In this paper, the interdependency of the magnetic anisotropy with the effect of cutting is studied in order to improve the necessary understanding of the material behavior.