Study On Modeling And Simulation And Control Strategy For Range-Extended Electric Vehicle

With the rapid growth of car ownership,energy shortages and exhaust pollution have become two major challenges in restricting the development of automobiles.Electric vehicles are the future direction of development which have the advantages of zero fuel consumption and less pollution.However,the battery technology is not yet mature,so the driving range of pure electric vehicle is limited.REEV(Range-Extended Electric Vehicle)is a hybrid vehicle equipped with APU(Auxiliary Power Unit).When the power is sufficient,the vehicle drive in the pure electric mode.When the power is not enough,the APU will work to drive the car.The research of the electric vehicle whose driving distance can be extended has a large research significance in the current.The main work of this thesis is as follows:Firstly,this thesis introduces the structure features and working principle,and analyzes the various working modes of REEV in detail.Secondly,according to the specific parameters and the target performance of the vehicle,the power source and transmission system of REEV are selected and their parameters are matched.Thirdly,based on Matlab/Simulink platform,the simulation model of vehicle powertrain was built by using experimental mode ling method.According to the model,the dynamic performance and economic performance simulation of REEV are carried out to verify the rationality of the parameters matching.Fourthly,this thesis introduces three typical control methods for REEV,and analyzes their advantages and disadvantages.In order to avoid the shortcomings of the typical strategy,this paper designed a new strategy combining fixed-point control with power following control of the fixed speed.In the CD(charge-depleting)stage,fixed-point control can extend the driving distance and enhance the dynamic performance of the vehicle.In the CS(charge-sustaining)stage,with the power tracking control of the fixed speed,it not only stabilizes the range of power fluctuations,but also avoids the frequent fluctuations of the engine speed.Finally,the simulation of the new strate gy is carried out to prove the feasibility of this strategy which provides the basis for the future development of the vehicle.