| With the continuous progress of human modernization,the destruction of the earth’s ecological environment is becoming more and more serious,and the crisis of resources and energy is becoming more and more serious.As one of the main forces of environmental protection and energy conservation,new energy electric vehicles are favored by all countries.However,there are still many problems to be solved in the process of its popularization and application,among which the dynamic response of pure electric vehicle powertrain is one of the problems.At present,there are few researches on the integrity of the power transmission system of pure electric vehicles.Generally,only the power battery and driving motor are studied separately,and the whole dynamic response of the whole power transmission system is not studied,which is necessary for the research of pure electric vehicles.Firstly,this paper analyzes the research status of power transmission system of pure electric vehicle,including the research status of power battery,the research status of drive motor,the research status of drive system and the research status of torsional damping structure.Summarize the shortcomings of the current research,according to the shortcomings of the current research,make the technical route of this paper.The main contents of this paper are as follows:(1)The power transmission system modeling of electric vehicle based on torsion spring.The power transmission system model of electric vehicle includes power battery model,PMSM model and control.The equivalent circuit model of power battery is studied and analyzed,and the rint model is established.The PMSM mathematical model is established,the PMSM mathematical model in the synchronous rotating coordinate system is derived,the principle of the hysteresis control method is studied and analyzed,and the adjustment method of the hysteresis control parameters is determined.Based on the dynamic analysis of the transmission system based on the torsion spring,the dynamic model is established,the dynamic analysis of the tire "brush" model is carried out,and the dynamic model of the "brush" model is established.(2)In order to optimize the motor control effect,according to the inverter model,the space vector pulse width modulation method is studied and analyzed,and the motor control parameters are optimized to improve the motor control effect,and the effectiveness of parameter optimization is verified through experimental comparison(3)The electromechanical coupling dynamic model of pure electric vehicle is established.This paper studies the dynamic characteristics of electromechanical coupling under the conditions of pit,sudden brake acceleration and uneven road conditions.For these sudden conditions,the electromechanical coupling model can accurately respond to the dynamic response of sudden conditions,which establishes the basis for the analysis of vehicle dynamic characteristics.(4)Aiming at the dynamic model of pure electric vehicle based on torsion spring,a simulation model is established on the platform of MATLAB / Simulink.Through the simulation model,the dynamic response characteristics of the system under the sudden load are analyzed.By changing the stiffness and damping of torsion spring,the dynamic response results of the system with the changes of stiffness and damping are analyzed.The laws of the dynamic response results of the system with the changes of stiffness and damping are obtained Through the optimization of the stiffness and damping values,the impact of the sudden load on the system structure is reduced by 76.6%,which proves the superiority of the torsion spring structure. |
