The possibility of distinguishing rotor cage bar faults in double squirrel cage induction motors on the basis of the stator current signal

This paper discusses the possibility of using the stator phase current waveform as a diagnostic signal for the detection of faults in the double squirrel cage induction motor. Current waveforms during the start-up state and steady state were analysed for variants of the given fault for both cages of the rotor. The usefulness of the assessment criteria of the rotor state of a single cage motor was examined for double cage machines. On the basis of the tests conducted on the double cage motor prototype, conditions were formulated for distinguishing faults in both cages of medium and high power machines.