Research On Power System Design And Control Strategy For 4WD Hybrid Vehicles With Electric Drive Axle

Energy crisis and environmental pollution caused by traditional car forced the world to study new energy vehicles technology to improve the present situation.Due to the limitation of technology and related facilities are not perfect,electric vehicles promotion were affected.Hybrid electric vehicles as the transition models of conventional vehicles and electric vehicles,has become the focus of the study.By studying the traditional automobile power system scheme and coupling hub motor with traditional vehicle power system,the design of powertrain system scheme of 4WD hybrid electric vehicles with electric drive axle was completed,a reasonable and effective electronic differential control system and vehicle control strategy were proposed,and the hybrid of traditional automobile was realized.4WD hybrid vehicles with electric drive axle have both of the fuel economy of hybrid vehicles and the pavement adaptability of 4WD vehicles,and a new way for the development of new energy vehicles are provided.Firstly,according to power system layout of the traditional car and the characteristics of the hub motor,the vehicle powertrain design was designed and the selection and parameter matching of hub motors and power batteries were completed by determining the vehicle dynamic performance parameters;Secondly,electronic differential control system and vehicle control strategy were completed,so as to improve the vehicle fuel economy and the pavement adaptability under the condition of safety driving;Finally,on the basis of the HIL simulation platform and vehicle integrated design,the reliability of the vehicle control strategy and the effectiveness of the electronic differential control system were verified.Simulation and test results show that the vehicle control strategy can effectively improve the vehicle fuel economy,especially in the NEDC cycle,can achieve 22.42% of the fuel saving rate.The electronic differential control system can dynamically distribute the both sides of the motor torque,improve the wheel slip rate deviation and improve the stability when the vehicle turns.