Motor core losses are greater than material core losses, which are measured by the Epstein test method. The increase in loss is due to a number of known factors; the rotational exciting field, the presence of plastic strain close to punching edge of manufactured motor sheets, assembling strains on the core material etc. An understanding of these effects is utmost importance in the designing of efficient motors. In this paper these effects on magnetic properties of Non-oriented electrical steel sheets are explained.
Key Words: Non-oriented electrical steel sheet, rotational exciting field, assembling strain, punching strain