纯电动汽车电驱动系统耦合动力学研究

Study on Coupling Dynamics of Electric Drive System of Pure Electric Vehicle

为研究纯电动汽车电驱动系统运行时的动态特性,考虑电磁时空激励和系统结构柔性,提出了一种适用于变速工况的一体化电驱动系统机电耦合动力学模型,并进行了仿真验证。以动力学分析为手段,重点研究了稳态、加速工况下电机转矩波动、齿轮误差和箱体柔性对电驱动系统动态特性的影响。研究结果表明:在稳态工况下,电机转矩波动对轴承力的影响不明显,齿轮误差会显著增加齿轮动态啮合力矩和轴承支反力的幅值,箱体柔性对齿轮动态啮合力矩的影响较小;在加速工况下,齿轮误差容易激发系统高频成分的共振,耦合箱体后容易激发与转频相关的低阶共振。

In order to study the dynamic characteristics of electric drive system of pure electric vehicle,considering spatio-temporal electromagnetic excitation and system structure flexibility,an electromechanical coupling dynamic model of integrated electric drive system suitable for variable speed conditions is proposed and verified by simulation. By means of dynamic analysis,the effect of motor torque fluctuation,gear error and housing flexibility on the dynamic characteristics of electric drive system is studied under steady-state and acceleration conditions. The study shows that the influence of motor torque fluctuation on the bearing force is not obvious under the steady-state condition,the gear error will significantly increase the amplitude of gear dynamic meshing torque and bearing reaction force,and the influence of housing flexibility on gear dynamic meshing torque is slight. Under the acceleration condition,the gear error is easy to stimulate the system high-frequency resonance,and the low-order resonance related to rotating frequency is also easy to be excited after coupling the housing.