ABSTRACT
A numerical detailed example for the magnetisation curve calculation gives a stronger feeling of magnitudes for its components in air and iron cores. In general, both stator and rotor currents produce a resultant field in the machine airgap and iron parts. For mild levels of magnetic saturation, usual in general purpose induction motors, the stator mmf fundamental produces a sinusoidal distribution of the flux density in the airgap (slotting is neglected). By balancing the magnetic saturation of teeth and back cores, rather sinusoidal airgap flux density is maintained, even for heavy saturation levels by balancing the magnetic saturation of teeth and back cores. If the teeth and back core saturation levels are notably different (oversaturated teeth is common), then the harmonics content of airgap flux density is rich. Flattened airgap flux distribution is obtained for oversaturated back cores. The voltage induced in the stator and rotor phases is of paramount importance for the induction machine behaviour.
