Torsional vibration suppression and electromechanical coupling characteristics of electric drive system considering misalignment

The torque ripples resulting from external electromagnetic excitation and mechanical internal excitation contribute to significant torsional vibration issues within electromechanical coupling systems. To mitigate these fluctuations, a passive control strategy centered around a multi-stable nonlinear energy sink (MNES) is proposed. First, models for electromagnetic torque, gear nonlinear meshing torque, and misalignment torque are established. Building upon this foundation, an electromechanical coupling dynamic model of the electric drive system is formulated. Sensitivity analysis is conducted to determine the sensitive nodes of each mode and to provide guidance for the installation of the MNES. The structure of the MNES is introduced, and an electromechanical coupling dynamic model with the MNES is established. Based on this model, the influence of the misaligned angle on the electromechanical coupling characteristics is analyzed. In addition, the vibration suppression performance of the MNES is studied under both speed and uniform speed conditions. Finally, experimental testing is conducted to verify the vibration suppression performance of the MNES. The results indicate that misalignment triggers the emergence of its characteristic frequencies and associated sidebands. Meanwhile, the MNES effectively mitigates the torsional vibrations in the coupled system, demonstrating suppression rates of 52.69% in simulations and 63.3% in experiments.