Effects of saturation on the forces in induction motors with whirling cage rotor

The effects of magnetic saturation on the radial magnetic forces in induction machines when the rotor is performing a cylindrical circular whirling motion are studied in this paper. Impulse method in the finite element analysis is used to calculate the forces and eccentricity harmonics from both the air-gap flux density and rotor currents. The forces are studied as a function of supply voltage in order to find the effects of saturation on them. The maximum radial force is found to be limited by saturation, which also couples the eccentricity harmonics together.