A Modified Model of Squirrel Cage Induction Machine Under General Rotor Misalignment Fault

Abstract

Abstract-A great deal of researches have so far been conducted on the analysis of eccentricity in induction machines. However, they mostly consider radial non-uniformity and neglect non-uniformity in the axial direction, but in practice, the axial non-uniformity due to rotor misalignment faults is quite common. This paper presents a modified model of a three-phase squirrel cage induction machine under different rotor misalignment conditions. For this purpose, general expressions for air gap and mean radius of induction machine, considering axial non-uniformity, have been developed. The proposed model is able to calculate the time varying inductances versus rotor angle for three-phase squirrel cage induction machines under general rotor misalignment, including static, dynamic and mixed rotor misalignment in the frame of a single program. Simulation results were verified by the experimental ones.