[IET] Characterisation of radial vibration force and vibration behaviour of a pulse-width modulation-fed fractional-slot induction machine

AuthorsJean Le Besnerais ; Vincent Lanfranchi; Michel Hecquet; Pascal Brochet; Guy Friedrich
StatusPublished in: IET
KeywordsInduction machine, magnetic noise, vibrations, fractional winding, experimental modal analysis, operational deflection shapes.


This paper presents the full analysis of the vibration behaviour responsible for audible magnetic noise in a PWM-fed fractional-slot induction machine, including theoretical predictions, numerical simulations, and experimental validations (stator modal analysis and deflection shapes visualisa- tion). Magnetic force waves due to slotting harmonics, pulse-width modulation (PWM) harmonics and their interactions are characterised in terms of nodes number, rotation speed, and propagation direction. It is shown in particular that some odd spatial order vibration waves appear due to fractional slotting, and that some combinations between slotting lines and PWM lines can be very noisy due to an elliptical mode natural frequency close from the switching frequency.

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