Noise of electric vehicle powertrain (EV HEV NVH) - case of BMW I3

Summary of e-NVH sound sample
Application BMW I3® (EV HEV NVH)
Electrical machine PMa-SynRM also called HSM (p=6 poles, Zs=72 stator slots)
Supply condition Run-up at max torque
Noise sources Electromagnetic, mechanical, aerodynamic
See also Hyundai IONIQ, NissanLeaf, Renault Zoe, Tesla X90

Measurement set-up

Noise is measured close to electric powertrain. An accelerometer is placed on the stator housing. A run-up is done with maximum torque up to 100 km/h in free field environment.

Sound file and spectrograms

Sound of BMW I3 electric powertrain during run-up at maximum torque
Sound of BMW I3 electric powertrain during run-up at maximum torque

Note: these sound files are the property of EOMYS; for authorized use in presentations, website, publications or technical work, please contact us

Spectrogramd of BMW I3 electric powertrain during run-up at maximum torque : Acceleration levels on the engine (left), Sound pressure level close to engine (right)
Spectrogramd of BMW I3 electric powertrain during run-up at maximum torque : Acceleration levels on the engine (left), Sound pressure level close to engine (right)

e-NVH interpretations

This sound file illustrates electromagnetically-excited noise of the electric powertrain of BMW I3 EV. High pitch, whining noise with increasing frequency is due to pole/slot electromagnetic excitations. Higher frequency sound occuring around multiples of switching frequency is due to PWM effects. PWM strategy is asynchronous with a switching frequency of 8kHz.

For a more detailed analysis, EOMYS provides technical trainings dedicated to EV HEV NVH.

Application to MANATE

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

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