Loading Spectrum Optimization Method for Torsional Vibration Suppression of Electric Vehicle Driveline in Motor Loading Process

During the driving and braking process of electric vehicles, the rapid and frequent adjustment of motor torque can cause significant rigid flexible coupling low-frequency torsional vibration, leading to significant NVH problems and reducing vehicle comfort. This article proposes a frequency spectrum optimization based motor torque smoothing method for transient vibration response during motor torque regulation in electromechanical composite transmission systems. Taking the classic three-stage variable speed loading curve as an example, the time parameters of the loading curve are optimized. Then, the optimized loading curve is applied to the dynamic torque loading process, and the system identification method is used to extend the designed optimal loading trajectory to the digital filter. Finally, the Simulink/Driveline high fidelity model was simulated and compared with passivation methods based on simple low-pass filters. The results show that, compared with the traditional filter, the designed spectrum optimization method has better low-pass characteristics, can effectively suppress the first-order modal frequency component in the motor torque, avoid free mode excitation.