Influence of mounting and coupling on the natural frequencies and acoustic noise radiated by a PWM controlled induction machine

Although the acoustic noise radiated by an electrical machine depends on the method of mounting and coupling to the load, to date, no detailed investigations have been reported. Due to the complexity of the machine structure, however, it is extremely difficult to predict the natural frequencies and to analyse the radiated acoustic noise. Therefore, in this paper, the influence of the foot mounting, the mechanical coupling, and the load on the acoustic noise radiated by a 3-phase, 6-pole, 36/32 stator/rotor slots, 1.5 kW PWM controlled induction motor drive is investigated experimentally, and its natural frequencies and noise spectra are analysed