| In the current automotive industry,electric vehicles have gradually become the main direction of research.However,the power battery in the market has been restricting the development of electric vehicles because of its charging and discharging characteristics,energy density,fast charging and other technical conditions.In the solution of electric vehicle,extended range vehicle has good engine working characteristics,superior emission performance,long driving range and low cost,which is a better choice in the intermediate solution of electric vehicle.The most important parts are the auxiliary power unit(APU),power battery and drive motor.The performance of the power battery has a decisive impact on the vehicle’s endurance.Therefore,based on this background,this paper improves a new type of logistics vehicle with added program,and proposes a dual battery power structure.At the beginning of this paper,a lot of information was consulted to understand the listing situation of extended range vehicles at home and abroad,and the development status of extended range electric vehicles;then,through reading the literature,the domestic and foreign scholars learned how to formulate control strategies;the research status of power battery was studied,and finally the focus of the research was to reduce the battery charging and discharging,less battery charging and discharging with high current.The configuration of double battery is proposed.The low-energy battery is discharged in low-energy condition,and the high-energy battery is discharged in high-energy condition.According to the power configuration of dual battery and the technical requirements of the whole vehicle,the parameters of power battery,generator,engine and power battery are matched and selected.Then the vehicle model of dual battery is established by CRUISE,the parameters of each component are input,and then the signal bus of the whole vehicle is connected;The interface module of CRUISE is used to set the parameters needed for CO simulation to complete the construction of vehicle model.This paper explores several control strategies of extended range electric vehicle,analyzes their advantages and disadvantages,and finally decides to design a rule-based thermostat + power following control strategy.According to the SOC of low-energy battery and high-energy battery and the power demand of the whole vehicle,it is divided into 18 situations,and the energy flow of the whole vehicle is determined according to each situation;the control strategy of regenerative braking is formulated,and the series regenerative braking is selected Strategy.Based on the above control strategy,the model is built on MATLAB Simulink.The model is divided into four parts: demand power calculation module,regenerative braking force calculation module,vehicle operation mode stateflow model,and range extender load rate selection module.Using full load acceleration condition,the acceleration time of 0-50 km / h and acceleration time of 0-100 km are obtained;using climbing slope condition,the maximum climbing slope is obtained;using CRUISE to generate the city + high speed random composite condition,setting the initial SOC of low-energy battery and high-energy battery,the effectiveness of the control strategy is verified;generating NEDC condition to calculate fuel consumption and power consumption;through simulation,1-50 km / h acceleration is achieved Therefore,Isight integrated CRUISE is used to establish the objective function of acceleration time and pure electric range.NSGA-Ⅱ algorithm is used to optimize the objective function,and the optimization result is good. |
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