NVH Comfort of Range Extenders for Electric Vehicles
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 (ICEs) 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. The basic REX concept is evaluated by considering power and fuel efficiency demands in combination with an interior noise forecast.