某款混动电动汽车低速粗糙异音分析及研究

Analysis and Research of Low-speed Rough Abnormal Noise of a PHEV

针对某款混合动力汽车在纯电模式下进行20%小油门开度低速行驶时,驾驶室内可以清晰识别机舱前部有粗糙异音产生。通过整车测试和频谱分析,确认该异音主要来源于混动变速箱前驱动电机侧。结合永磁同步电机噪声机理分析和总成EOL台架试验对比,进一步判断该异音主要由24阶次及其倍频构成(电机构型为8极48槽),且在特定电机转速区间及频率区间呈现耦合现象,即粗糙特征。后期通过对电机定子的设计优化,焊接及绝缘漆工艺改善,谐波注入优化,经过整车多轮测试比对,基本消除了低速粗糙异音,车内声品质得到明显改善和提升。

For a hybrid vehicle,when driving at low speed with 20%small throttle opening in the EV mode,the rough abnormal noise in the front of the cabin can be clearly identified.Through vehicle testing and spectrum analysis,it was confirmed that the abnormal noise mainly came from the front drive motor side of the hybrid gearbox.Combined with the noise mechanism analysis of the permanent magnet synchronous motor and the comparison of the EOL bench test,it is further judged that the abnormal noise is mainly composed of 24th order and its frequency doubling order(The drive motor is 8 poles and 48 slots),and the coupling phenomenon is shown in the specific motor speed range and frequency range.Through the design optimization of the motor stator,the improvement of welding process,adoption of the harmonic injection,after several rounds of vehicle testing,the low-speed rough abnormal noise was basically eliminated,and the NVH performance was significantly improved.