Vibration mechanism and suppression strategy for the electromechanical-thermal coupled system in distributed drive electric vehicles

Distributed drive electric vehicles face vibration and noise challenges due to the coupling of high-frequency electromagnetic excitation, time-varying meshing stiffness, and thermal deformation, forming a typical electromechanical-thermal multi-field coupled vibration. A systematic investigation into this coupling mechanism and suppression strategy is presented. An electromechanical-thermal multi-field dynamic model is established to reveal multi-field interactions. A hierarchical collaborative suppression method is proposed: structural optimization reduces transmission vibration; control-level model predictive control with harmonic current injection mitigates electromagnetic excitation; thermal-level coolant regulation suppresses thermally induced vibration. Dynamometer tests show that the proposed method reduces critical component vibration by 5 dB(A), significantly improving NVH performance. This study offers a complete technical pathway for low-noise design from mechanism analysis to suppression implementation.