Time-frequency vibration analysis for the detection of motor damages caused by bearing currents

摘要: Abstract Motor failure due to bearing currents is an issue that has drawn increasing industrial interest over recent years. Bearing usually appear in motors operated by variable frequency drives (VFD); these may lead common voltage modes which cause induced the motor shaft are discharged through bearings. The presence of only few months after system startup. Vibration monitoring one most ways for detecting damages caused circulating currents; evaluation amplitudes well-known characteristic components vibration Fourier spectrum associated with race, ball or cage defects enables evaluate condition and, hence, identify eventual damage currents. However, inherent constraints transform complicate detection progressive degradation; instance, some cases, other mask be confused defect-related while, analysis not suitable non-stationary nature captured signals. Moreover, fact this implies lose time-dimension limits amount information obtained from technique. This work proposes use time-frequency (T-F) transforms analyse data affected experimental results real machines show via T-F tools provide significant advantages current damages; among other, techniques enable visualise degradation while providing effective discrimination versus related fault. their application valid regardless operation regime machine. Both factors confirm robustness and reliability interesting alternative type induction motors.