Characterization of higher harmonic frequency components in noise and vibrations generated by inverter-fed three-phase induction motors

Abstract

This paper introduces a new method to characterize harmonic frequency components of the noise and vibrations generated by the three-phase induction motors, the speed of which is controlled by an inverter. Because the current generated by the inverter generally deviates from a pure harmonic wave, there appear various higher harmonic components in the electromagnetic force waves. The electromagnetic force waves are given by square of the magnetic flux density waves and drive the structure to vibrate and radiate noises. But, if we choose significant harmonic components from the flux density waves measurements in comparing with the theoretical model rather than from the electromagnetic force waves, the number of possible combinations of the harmonics may be reduced. By so doing we can find sources of the noise and vibrations more efficiently.