Influence of magnetic saturation on rotor bar current waveform and performance in induction machines

This paper investigates the influence of magnetic saturation on the rotor bar current waveform and performance characteristics of a squirrel-cage Induction Machine (IM). The levels of iron saturation in different parts, including stator and rotor back iron, tooth body and tooth tips etc., are examined and their influences are investigated, while the dominant part which causes the non-sinusoidal rotor bar current waveform is identified. It has revealed that the magnetic saturation, particularly in the rotor tooth, has a significant effect on the bar current waveform and the phenomenon is explained in depth.