Investigation To Torsional Vibration And Control Of Electric Vehicle Drivetrain

The rapid development of China's economy has contributed to the growth of residential car ownership,but also exacerbated the energy shortage,environmental pollution and traffic congestion and other issues.Electric vehicle has the advantages of energy saving and environmental protection,and it has become a hot spot in the research and development of major automobile manufacturers.Meanwhile,People's demand for automotive NVH performance is getting higher and higher.Since the torsional vibration of vehicle drivetrain has an important influence on the quality of NVH,it is of great practical significance to analyze torsional vibration of electric vehicle drivetrain.Although it is able to meet the general demands of the vehicle power performance with the main reducer with fixed speed ratio,it has high requirements for the performance of the drive motor and it is not conducive to reduce production costs.The electric vehicle can effectively reduce the power demand of the drive motor and improve the operating efficiency of the motor through the two speed transmission.This paper focus on the torsional vibration of the drivetrain for an electric vehicle equipped with the two speed automatic transmission(2AMT).First,the mathematical model of the torsional vibration and the multi-body dynamics model based on ADAMS are established to analyze the vibration characteristics of the drivetrain for the electric vehicle.Second,the vector control model of permanent magnet synchronous motor(PMSM)is set up under the environment of Matlab/Simulink.The simulation results of the _di=0 control strategy and the maximum torque per ampere control strategy are compared and analyzed,and the superiority of the maximum torque per ampere control strategy is verified.Next,an electromechanical coupling simulation model of the drivetrain is built by combining the dynamics model of torsional vibration of transmission system and the vector control model of PMSM.By using the coupling model,the torsional vibration response characteristics of the drivetrain and the influence of the related parameters on the torsional vibration of the drivetrain are analyzed.Finally,a feedforward-feedback torsional vibration controller is designed by the analysis of the two-degree-of-freedom simplified model.The simulation shows that the feedforward-feedback torsional vibration controller can effectively reduce the torsional vibration for the electric vehicle drivetrain and improve the ride comfort.