关键词: 纯电动汽车；电驱总成；电磁噪声；NVH

Abstract: The whine noise of a battery electric vehicle accelerating to 70 km/h seriously affects the sound quality of the vehicle. Combined with the vehicle subjective and objective test evaluation, it is found that the 6th order electromagnetic noise contributes to the problem. The mechanism analysis of this noise is carried out by means of modal test, semi-anechoic chamber bench test and so on. It is determined that the mechanism is the forced vibration caused by the deviation of the co-axiality of the motor stator and rotor, which lead to the uneven magnetic density of the air gap, resulting in the peak of the electromagnetic 6th order vibration at 450 Hz, and the 6th order noise is further amplified through the resonance of the upper cover of the controller. In order to effectively solve the problem of electromagnetic 6th order noise, the optimization of the motor stator processing technology and the controller cover are implemented from the two aspects of noise source and transfer path, and the effectiveness of the scheme is verified by semi-anechoic chamber experiments. It provides valuable experience and engineering value for noise, vibration, harshness (NVH) performance of the electric drive of battery electric vehicles.

Key words: Battery electric vehicle; Electric drive; Electromagnetic noise; NVH