Optimization of Mount Bracket on Whine Noise Performance for a Battery Electric Vehicle

Recently, the market share of electric vehicles is becoming increasingly obvious. It is expected that electric vehicles are quieter than fuel vehicles. Actually, without the cover of low-frequency engine noise, the high-frequency noise of electric vehicles is more prominent, which seriously affect the perceived sound quality. The present work is related tonal noise resulted from electric drive system (EDS), which is one of the fundamental noise sources for battery electric vehicle (BEV). The dominant noise sources observed in the vehicle interior are 26th and 36th orders for reducer and drive motor separately. Poor vibration isolation of right mounting system is the fundamental cause identification of EDS noise which has been investigated with objective measurements and simulation tools. Dynamic stiffness analysis is carried out to optimize the passive bracket. An engineering solution is implemented to enhance bracket to improve resonance effect. The test results after improvement scheme has a 10dB(A) noise reduction for the whine noise of vehicle interior.