The most appreciated driving characteristics of electric vehicles are the quietness and spontaneous torque rise of the powertrain. The application of range extenders (REX) with internal combustion engines (ICE) to increase the driving range is a favourable solution regarding costs and weight, especially in comparison with larger battery capacities. However, the NVH integration of a REX is challenging, if the generally silent driving characteristics of electric vehicles shall remain preserved.
This paper analyses key NVH aspects for a REX design and integration to fulfil the high expectations regarding noise and vibration comfort in an electric vehicle environment. The ICE for a REX is typically dimensioned for lower power outputs, incorporating a low number of cylinder units, which is even more challenging concerning the NVH integration. It will be explained that sophisticated, innovative technologies are required on component and vehicle side to ensure best possible NVH comfort. On component side, essential excitations must be addressed. In that context, active countermeasures like “FEVcom” for vibration control are introduced. On vehicle side, tailored powertrain mounting concepts are presented, applicable to reduce the residual vibrations of a REX. Finally, an approach for a NVH focused operating strategy is outlined.