Evaluation of current and vibration signals for squirrel cageinduction motor condition monitoring

摘要

This paper reviews aspects of online condition monitoringtechniques for detecting broken rotor bars in squirrel cage inductionmotors, by evaluating both current and vibration signals and takingcognisance of interbar currents. The paper shows that significantinterbar currents reduce the unbalance brought about by a broken rotorbar, and thus why it is necessary to focus attention elsewhere in thecurrent spectrum to diagnose a broken bar. This paper also explains thetechnique of monitoring the vibration spectrum and the effect ofinterbar currents which produce tell-tale components in the vibrationspectrum. Two separate online condition monitoring techniques can beused in conjunction with one another to provide an accurate diagnosis ofsquirrel cage induction motors with broken rotor bars. The theoreticaland experimental results provide significant proof of the validity ofthese two online condition monitoring techniques. The naturalprogression is to provide a software program to perform the intricatemathematical analysis for industrial use