Vibration, Acoustic Noise Generation and Power Quality in Inverter-fed Induction Motors

The use of inverter-fed electric motors in the industry is currently of great importance. These inverters generate harmonics and noise in the current and voltage signals, which affect the generation of vibration and acoustic noise. The power supply should be considered for establishing fault thresholds in a diagnostic system or meeting certain specifications for acoustic noise and vibrations. This paper presents an experimental analysis of the energy quality provided by variable frequency drives and the power grid as they generate diverse conditions for fault-diagnosis techniques. The effects produced by the vibration and sound signals harmonics are presented and evaluated quantitatively by the calculation and comparison of the vibration and sound energy of the signals generated by the frequency drives and the power grid. Also, the spectra of vibration and sound are obtained for steady-state and startup transient operation.