Whine noise from the electric powertrain system of electric vehicles, including electromagnetic noise and gear-meshing noise, significantly affects vehicle comfort and has been getting growing concern. In order to identify and avoid whine problems as early as possible in the powertrain development process, this paper presents a vibration and noise simulation methodology for the electric powertrain system of vehicles under speed-varying operating conditions. The electromagnetic forces on the stator teeth of the motor and the bearing forces on the gearbox for several constant-speed operating conditions are obtained first by electromagnetic field simulation and multi-body dynamic simulation, respectively. Order forces for the speed-varying operating condition are generated by interpolation between the obtained forces, before they are applied on the mechanical model whose natural modes have been calibrated in advance by tested modes. The whine noise radiated from the powertrain is then obtained based on acoustic boundary element analysis. The simulated bearing forces indicate that the overlooking of the motor torque ripple does not result in significant loss in simulation accuracy of electromagnetic noise. The simulation results and tested data show good consistency, with the relative frequency deviation of local peaks being less than 8% and the error of the average sound pressure level (SPL) being mostly below 10 dB (A).

中文翻译：

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变速操作条件下电动汽车动力总成系统的振动与噪声分析

电动汽车电动动力总成系统发出的啸叫声，包括电磁噪声和齿轮啮合噪声，极大地影响了车辆的舒适性，并且受到越来越多的关注。为了在动力总成开发过程中尽早发现并避免发声问题，本文提出了一种在变速操作条件下的车辆动力总成系统的振动和噪声仿真方法。首先通过电磁场仿真和多体动力学仿真分别获得在几种恒速运行条件下电机定子齿上的电磁力和齿轮箱上的轴承力。通过在获得的力之间进行插值来生成变速操作条件下的命令力，在将其应用于自然模式已通过测试模式预先校准的机械模型上之前。然后基于声学边界元分析获得动力总成发出的啸声。模拟的轴承力表明，忽略电动机转矩波动不会导致电磁噪声的模拟精度显着降低。仿真结果和测试数据显示出良好的一致性，局部峰值的相对频率偏差小于8％，平均声压级（SPL）的误差大多低于10 dB（A）。模拟的轴承力表明，忽略电动机转矩波动不会导致电磁噪声的模拟精度显着降低。仿真结果和测试数据显示出良好的一致性，局部峰值的相对频率偏差小于8％，平均声压级（SPL）的误差大多低于10 dB（A）。模拟的轴承力表明，忽略电动机转矩波动不会导致电磁噪声的模拟精度显着降低。仿真结果和测试数据显示出良好的一致性，局部峰值的相对频率偏差小于8％，平均声压级（SPL）的误差大多低于10 dB（A）。