Abstract
A technique for calculating the iron losses in a cage induction motor is demonstrated using time-stepping finite-element analysis, which has given good agreement with measured iron losses under both no-load and full-load conditions. The model has been used to investigate the variation of iron loss with load. It has been shown that the iron losses increase significantly from no-load to full-load; and that this increase is due entirely to the increase in the harmonic fields caused by slotting.