| Abstract |
The paper investigates the acoustic noise radiated from two nominally identical induction motors when fed from
sinusoidal, quasi-square six-step, and asymmetric regular sampling subharmonic and space vector PWM converters. 1l1e theory for analysing the noise spectrum is developed further to account for the interaction between the motor and drive, and is used to identifY the dominant noise components. It is shown that manufacturing tolerances can result in significant differences in t11e noise level emitted from nominally identical motors, and that mechanical resonances can result in extremely high noise emissions such resonances can be induced by stator and rotor slot airgap field harmonics due to the
fundamental component of current, and by the interaction between the airgap field harmonics produced by the fundamental and the PWM harmonic currents. Therefore, the PWM strategy will be critical only if the dominant cause of the fitted noise is the interaction of the fundamental airgap field and PWM harmonics. |
