Research On Control Strategy Of Electric Vehicle Energy Recovery

In this thesis,an electric vehicle of DongFeng brand as the research object,according to the characteristics of the target electric vehicle which is rear-wheel drive by "Basic Analysis,Strategy Formulation,Modeling and Simulation,CAN Network Simulation,Vehicle Validation",fully analyzing the basic structure of electric vehicle energy recovery principle and influencing factors,using the method of model-based design,the energy recovery control strategies was constructed in the sliding condition and braking condition,the Simulink-Cruise co-simulation of the control strategies have been established.In the aspect of controlling the regenerative braking torque of the motor,some factors are analyzed what are affecting the energy recovery to verify the energy recovery when the vehicle model is operating according to the vehicle conditions which are preseted.In the terms of vehicle test,some vehicle validations about test experiments are accomplished in the actual sliding and braking conditions.What’s more,the system has been designed which is used to the energy recovery control CAN(Controller Area Netwok)network simulation,using the real data of vehicle test to CANoe simulation verification,they visually display that are vehicle real-time operating status and energy recovery effects.First of all,based on the structural principle of the energy recovery system of the target vehicle,the driving conditions,transmission gear,motor characteristics,battery SOC(State of Charge),control strategy and operating environment are discussed in details.When braking,the stability and safety of the vehicle,brake regulations,test standards,riding comfort and other constraints on the energy recovery of electric vehicles.Secondly,according to the process about making the control strategy,arounding to the center view that is to recovery energy as much as possible under the premise of satisfying the stability and safety of vehicles,the energy recovery control strategy has been established respectively for two conditions of sliding and braking.Then,based on the model-based design method,the MATLAB/Simulink model is established which is electric vehicle energy recovery control strategy.The AVL Cruise is used to build the EV model and the Simulink-Cruise co-simulation software set up.According to the basic idea of "control variable method",these simulation conditions to verify the influence of various factors on the regenerative braking torque of the motor,analyze the specific effects,verify the correctness of the co-simulation model and control strategy,and conduct vehicle test verification in actual sliding conditions and braking conditions,the results show that the control strategy works well.Finally,the system design about energy recovery control CAN network simulation is completed,and the CANoe software is used to simulate the system based on the existing real vehicle test data.The results fully verify the accurate and reliable operation of the energy recovery system.The proposed energy recovery control strategy for electric vehicles,the energy recovery rules obtained and the CAN network simulation system for energy recovery control all will provide references for further research on the energy recovery of electric vehicles,and have certain guiding significance for improving the energy recovery rate of electric vehicles to improve vehicle energy utilization and driving range.