Noise of a PWM-supplied traction machine during braking

Summary of e-NVH sound sample
Electrical machineDC Motor
Supply conditionRun-down under PWM
Noise sourcesElectromagnetic, aerodynamic, mechanical
See also 

Measurement set-up

Noise is measured at passenger seat.

Sound file and spectrograms

Sound of a DC traction motor during braking phase with changes of PWM strategy

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E-NVH interpretations

This sound file illustrates acoustic noise experienced during braking phase of a subway. One can observe discontinuous changes of the main noise frequency, which shows that noise is driven by Pulse Width Modulation effects (change of the synchronous switching frequency according to converter strategy).

Application to MANATEE

MANATEE software can be used to quickly calculate NVH due to electromagnetic forces both in early design and detailed design phase, including PWM and slotting effects.