What are NVH issues?

NVH stands for noise, vibration and harshness. It is a technical field concerned with the perception and measurement of noise and vibration in vehicles and machines.

NVH in electric motors

NVH is particularly relevant for electric motors because they are very quiet compared with combustion engines. As a result, other sources of noise come to the fore.

Magnetic imbalances deserve particular mention: they can arise from the electromagnetic forces inside the motor and cause oscillations and vibrations that affect ride comfort and the service life of the drive. Besides these magnetically induced effects, bearing noise, gearbox components and switching operations also play a role.

Detecting and minimising these NVH influences requires dedicated test systems and precise analysis methods.

How magnetic field measurement finds magnetic defects early is covered in Why measure magnetic fields in electric motors?