Dynamic Analysis And Design Of Energy Regenerative System In The Braking Process Of Electric Vehigle

Electric vehicles (EVs) can solve the problems of energy shortage andenvironmental pollution brought by the traditional fuel-consumption vehicles. Theregenerative braking is an effective mean to solve the problem of short driving distanceof EVs per charge which significantly constrains the development of EVs. Meanwhile,it can improve the energy usage efficiency and reduce the energy consumption and theenvironmental pollution due to the replaced old batteries.In this thesis, we have developed the research on the regenerative braking ofEVs and completed the dynamic analysis of the vehicle in the process of braking. Someinnovative results are obtained as follows:(1) In the thesis, we redistributed the braking force among front wheels, rearwheels, and the mechanical motor according to the desired force distribution based onthe dynamic analysis of the vehicle in the process of regenerative braking.(2) we designed a regenerative braking force controller based on the fuzzy logicwhich had four inputs including the driver's braking requirements, vehicle speed,batteries'SOC and batteries'temperature. The controller can ensure the driving safety,stability, comfort and battery safety.(3) according to the control strategy, we designed the control flow, edited therelevant files and modified the relevant modals in the vehicle simulation software-ADVISOR using the tool MATLAB/SIMULINK.(4) based on the analysis of the braking line using fluid mechanics, we designeda braking force distribution valve which can realize the arbitrary distribution of thebraking force among front wheels, rear wheels, and the mechanical motor.(5) we designed and optimized the hardware and the hardware in-the-loopsimulation system so that the design of the vehicle controller can facilitated.Through the software testing and hardware in-the-loop simulation, the controlstrategy proposed in this thesis can distribute the braking force among the front wheels, the rear wheels and mechanical motor according to the desired force distribution.Braking safety, stability, comfort and battery safety of the vehicle can be ensured andthe total energy usage efficiency of EV can be improved about 10% and the drivingdistance of EV per charge can be extended effectively.