Study On Regenerate Brake System Of Plug-in Hybrid Electric Vehicle

Regenerative braking is one of the key and advanced techniques for HEV, whichwill recover and reuse the kinetic energy when HEV is braking or decelerating. In thispaper, we select Changfeng CS7Plug-in HEV for the study subject and have a deeplytheoretical researching, control strategy simulation and system simulation.Firstly, by comparing the advantages and disadvantages of the different HybridElectric Vehicle structure’s characteristics, it shows that the parallel Plug-in HybridElectric Vehicle has obvious advantage of the power transmission and saving energyconsumption. To meet the needs of the vehicle based on the power balance equation,the vehicle’s dynamic parameters are matched and the key components of the vehicleare selected. Then, according to vehicle dynamic theory, the dynamic analysis of thevehicle is presented in the braking process. The compound strategies for braking forcedistribution and control of PHEV which can achieve maximum energy recovery with apremise of ensuring the brake safety are proposed and compared with traditionalvehicle’s brake force distribution strategies.Secondly, the engine and the motor numerical models are established by theexperimental modeling method in the Matlab/Simulink environment. By thetheoretical modeling method, the whole vehicle model and batteries and CVT withfluid torque converter models are built using mathematical formulas. According to theAdvisor embedded reference models, the wheel model and the driver model areestablished. In the driver model, the vehicle speed can be tracked well by acceleratePI controller and brake PID controller.Finally, the compound strategy for braking force distribution and control ofPHEV are simulated. The results show that the compound strategy can improve theregenerative braking system utilization efficiency, thereby increasing the efficiency ofenergy recovery. Then, the brake force distribution and energy recovery efficiency areanalyzed in Circle FTP-75under diffident road adhesion coefficient, and the resultindicates that the adhesion coefficient can be increased to improve the recoveryefficiency. Lastly, the simulation result of Circle NEDC shows that the vehicle’sadvantage is obvious. In conclusion, the research lays a solid foundation for furtherresearch and improvement.