Abstract

This paper first presents the analytical models of an ALSTOM simulation software, DIVA, which computes the vibratory and acoustic behavior of a variable-speed induction machine due to Maxwell forces. This radial magnetic pressure in the air-gap makes the stator vibrate in the audible range, creating the so-called magnetic noise characterized by a high tonality. On the ground on these analytical models, the main magnetic vibrations due to slotting, pulse-width modulation (PWM) harmonics and their interaction are then analytically characterized. Their number of nodes, velocity and propagation direction are experimentally validated by visualizing the stator deflection shapes. Finally, some experimental validations of the simulation tool are presented. On the ground of both analytical results and simulations, it is shown that some quieter motors can be designed acting on the motor geometry (especially slot numbers) and PWM strategy.

Preprint and full paper

The full paper can be accessed on Noise Control Engineering Journal. The pre-print can be downloaded here: