Finite element diagnosis of rotor faults in induction motors based on low frequency harmonics of the near-magnetic field

The influence of different faults of squirrel-cage rotor in induction motors on the near-magnetic field are studied in this paper. The 2D finite element analysis of electromagnetic field is used to investigate the detection of broken rotor bars and rotor eccentricity faults. This analysis is focused on the low frequency harmonics of the near-magnetic field, which are much modified under faulty conditions and less attenuated by the motor frame.