Measurement techniques for vibration and acoustic noise of electrical machines

The conventional methods for the measurement of resonant frequencies, vibration and noise in electric machines are laborious and very time consuming. This paper presents laboratory techiques for the measurement of resonant frequencies, vibrations and noise based on digital processing of signals. The method uses the processing of different signals acquired from several transducers with the help of a data acquisition system and a personal computer. The measurement set-up is also used to determine the electromagnetic excitation forces, which produce vibrations in a machine. This measurement procedure is quite fast and gives good accuracy. Experimental results on the resonant frequencies and vibration behaviour of stators is presented. Experimental information on the electromagnetic excitation forces produced in an induction motor is also provided