Modal characteristics of electric vehicle powertrain considering electromagnetic effect

In this paper, the modal characteristics of an electric powertrain considering electromagnetic effect are directly obtained by solving the parameter matrix of the system state space equation. Open loop controller and PI controller are applied to the electric powertrain respectively. The natural frequencies and mode shapes under different loads and PI controller gains are studied. The influence of electromagnetic effect on gear load and motor current under impact load is also analyzed. Results indicate that the magnetic field and the PI controller introduce a low-order rotational mode respectively. These two modes play a significant role in the load impact process. Furthermore, the natural frequencies of the low-order modes change with the load and PI controller gains. The results provide theoretical support for electromechanical system design and dynamic load research.