结构-电磁激励下某电驱总成噪声控制

针对某电动汽车电驱总成的噪声问题,依据电驱总成车内噪声产生机理,进行整车状态声振特性测试,运用不同工况组合下的频谱特征和阶次特征等分析方法,识别出该电驱总成噪声问题为结构共振和电磁激励所致。针对结构共振问题,考虑电驱总成结构耦合特性、电机材料复杂多样性和线圈绕组质量,建立电驱总成有限元分析模型,求解出电驱总成的模态和振动响应,并通过敲击法模态试验得到模态参数进而对有限元模型进行验证,在此基础上以模态应变能为依据对电驱总成结构的局部刚度进行优化,提升结构共振频率,降低共振风险。针对电磁激励问题,以电驱总成中的永磁同步电机为研究对象,建立电磁仿真分析模型,以影响磁通密度的转子槽口的槽形、槽宽、槽深和槽间角度4个因素建立正交试验设计表,通过极差值得到各因素对齿槽转矩和输出转矩的影响水平,最后以降低齿槽转矩、加工工艺简单和对输出转矩影响小为目标,运用16组具有代表性的电磁方案,完成256个参数组合的寻优,并对优化方案进行了数值仿真计算。研究结果表明：优化方案的改善效果较显著;研究可为电动汽车车内噪声改善提供试验技术支持,并为电驱总成的结构共振噪声和电磁噪声控制提供方法参考。

Noise Control for Electric Drive Assembly Under Structure-electromagnetic Excitation

To address the noise problem affecting the electric drive assembly of an electric vehicle, noise, vibration, and harshness testing was performed based on the interior noise generation mechanism of the electric drive assembly. Methods such as spectrum analysis and order analysis were used under different combinations of working conditions, and the noise problem was found to be caused by structural resonance and electromagnetic excitation. For the structural resonance problem, considering the structural coupling characteristics of the electric drive assembly, the complex diversity of motor materials, and the quality of the coil windings, a finite element model (FEM) of the electric drive assembly was established, and the modal and vibration responses of the electric drive assembly were calculated. The FEM model was validated through a hammering modal experiment. Then, the local stiffness of the structure of the electric drive assembly was optimized based on the modal strain energy, which increased the structural resonance frequency and reduced the resonance risk. For the problem of electromagnetic excitation, the permanent magnet synchronous motor in the electric drive assembly was taken as the research object. An orthogonal experimental design table was established based on the four factors including the slot shape, slot width, slot depth, and slot angle of the flux density rotor slot. The electromagnetic simulation model was modified and solved according to the motor parameters and operating conditions. The level of influence of various factors on the cogging torque and output torque was determined through the range value. Finally, with the goal of reducing the cogging torque, simplifying the processing technology, and minimizing the impact on the output torque, 16 groups of representative electromagnetic schemes were used to determine the best parameter from 256 optimizations, and simulation calculations were performed on the optimization scheme. The calculation results show that the improvement resulting from the optimization scheme is significant. This research provides experimental support for eliminating noise in electric vehicles and provides a reference method for determining the structural resonance noise and for electromagnetic noise control of electric drive assemblies.