Experimental investigations of noise and vibration in electric machines

Noise and vibration in electric machines is a significant issue to take into account when high performance is wanted to be achieved. During operation, vibration frequencies which match the resonance frequencies of the structure are absolutely to be avoided, because of their negative effect on the machine performance and the risk of mechanical damage. In this paper, a test procedure is described to check if this condition is achieved for a sample induction machine. In particular, two kinds of test are performed: a modal test, which gives information about the resonance frequencies, and a test with the machine operating at different speeds, in order to evaluate the frequency spectrum of the vibrations during working condition.