Summary of e-NVH sound sample

Application	Subway
Electrical machine	Outer rotor Surface Permanent Magnet Synchronous Machine (SPMSM)
Supply condition	Run-up at max torque under non sinusoidal supply
Noise sources	Electromagnetic, mechanical
See also

Measurement set-up

Noise is measured at passenger seat close to electric powertrain.

Sound file and spectrograms

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E-NVH interpretations

This sound file illustrates electromagnetically-excited noise of a synchronous motor. High pitch, whistling noise is due to resonances between pole/slot electromagnetic excitations and the outer rotor structural modes. The PWM effects cannot be heard and a significant part of the noise comes from open circuit operation.

Attached documents

Sound of a traction synchronous machine during run-up