Study On Powertrain Parameter Matching And Energy Management Strategy For Parallel PHEV

In the face of increasingly severe environmental pollution and fossil energy crisis,automotive emissions and fuel consumption regulations are becoming more and more stringent,automotive electrification has become an inevitable trend of automotive development.Plug-in hybrid electric vehicle(PHEV)is an important transition product from traditional automobile industry to pure electric drive.It is an ideal choice to solve the problems of immature battery technology,insufficient charging infrastructure and lack of sustainable power generation.As the core technology of plug-in hybrid vehicle,power system matching and energy management strategy plays an important role in energy saving and emission reduction of plug-in hybrid vehicle.It is a hot research topic in the field of hybrid vehicles.In this paper,the parallel plug-in hybrid vehicle is studied,focusing on the power system matching and energy management strategy.According to the dynamic performance index of the whole vehicle under various modes and the pure electric driving mileage,the traditional dynamic matching method are used to calculate the parameters of the power system,and the parameters of the power system satisfying the requirements are obtained.Based on the instantaneous optimization strategy,the energy management strategy is designed,and its power consumption law and torque distribution law under different travel mileage,different electric power and different driving conditions are analyzed.Aiming at the disadvantage that the optimization strategy is difficult to apply to a real vehicle,a rule strategy is designed based on the above rules,which mainly includes the rule of using battery power with piecewise linear descent and the strategy of torque distribution based on the high efficiency region of the engine.The battery energy consumption is divided into pure power consumption stage,mixed power consumption stage and power sustaining stage.To meet the principle of making full use of electricity and reducing electricity sustaining stage,to achieve higher fuel economy and battery power utilization.Furthermore,the influence of the key parameters of the rule strategy,the mixed power consumption threshold and the boundary of the engine high efficiency zone,on the control strategy is analyzed in detail.On this basis,the optimization measures of the rule strategy are put forward to develop the adaptive rule control strategy adapting to different travel mileage and different battery initial state of charge.A method for estimating pure electricity driving mileage and total driving mileage is also provided.The vehicle simulation platform is built in Matlab,and the improved rule strategy is simulated and analyzed,and compared with the control effect of traditional CD-CS strategy,initial rule strategy and instantaneous optimization strategy.The simulation results show that the improved rule strategy can achieve lower fuel consumption than the CD-CS strategy under different travel mileage and different initial power consumption,and achieve similar battery power utilization,thus proving the superiority of the proposed energy management strategy for plug-in hybrid electric vehicles.These methods provide useful reference for PHEVs’ development.