The New Challenges of NVH Package for BEVs 2019-01-1452

Battery electric vehicles (BEVs) bring new challenges when it comes to NVH package development, which are affected by many new factors. The noise sources from the powertrain are different, for instance due to the presence of tonal components, strong harmonics and potential whining noise. Another important aspect is the missing effect of masking noise from a combustion engine. As a consequence, other noise sources, such as tires, become more predominant. This means that the NVH package has to be re-engineered considering new noise sources and cannot just be significantly decontented in general. At the same time, NVH package weight reduction should at least partly counterbalance the vehicle weight increase due to the presence of a large and heavy battery pack in order to maximize the driving range. In the early days of BEVs, OEMs mostly carried over technologies used on combustion engine vehicles to electric cars. With the development growth of specific vehicle platforms for electric cars, NVH strategies and technologies might strongly change.

The aim of this paper is to discuss the future NVH package of BEVs. It starts with subjective acoustic testing results and noise contribution analysis. On the basis of this study, future directions for exterior and interior trim parts are presented. This covers the effect of absorptive underbody and e-motor treatments, the challenge around battery pack integration, and the change of acoustic concept for interior parts.