The influence of the electromagnetic parameters on the torsional dynamics of the electric vehicle powertrain is studied by considering the electromechanical coupling effect. By adding the electromagnetic torque on the drive side, the powertrain is simplified as nonlinear drive-shaft model. The number, stability, and bifurcation conditions of the equilibrium points of the nonlinear drive-shaft model are deduced. Based on the averaged equations and the amplitude-frequency response equation, the stability and bifurcation conditions, such as fold bifurcation and Hopf bifurcation, of the resonance curve are discussed. The influence of electromagnetic parameters on the torsional dynamics is studied by simulation. It is shown that with the change of the parameters, the number as well as the stability of the equilibrium points may be changed which is affected by fold bifurcation. It is also shown that the resonance curve may lose its stability when fold bifurcation happens. By limiting the parameters in the region without fold bifurcation, the unstable dynamics of the resonance curve can be controlled.

考虑机电耦合效应，研究电磁参数对电动汽车动力总成扭转动力学的影响。通过在驱动侧添加电磁转矩，动力系统被简化为非线性驱动轴模型。推导出非线性传动轴模型平衡点的数量、稳定性和分岔条件。基于平均方程和幅频响应方程，讨论了谐振曲线的稳定性和分岔条件，如折叠分岔和Hopf分岔。通过仿真研究了电磁参数对扭转动力学的影响。可以看出，随着参数的变化，平衡点的数量和稳定性可能会受到折叠分叉的影响。还表明，当发生折叠分叉时，共振曲线可能会失去稳定性。通过限制没有折叠分叉区域的参数，可以控制共振曲线的不稳定动力学。