Research On Energy Management Strategy Of Plug-In Hybrid Vehicle Considering Battery Decay Characteristics

With the increase of energy crisis and environmental pollution,the emergence of new energy vehicles will undoubtedly bring about a turnaround for major issues facing the automotive industry.Plug-in hybrid vehicles have become hot spots for new energy vehicles.It not only has the characteristics of energy saving and environmental protection of traditional internal-combustion vehicles with strong endurance and pure electric power.In this paper,the energy management strategy of plug-in hybrid vehicles is studied based on the battery attenuation strategy.This dissertation focuses on the system structure and working mode of the plug-in hybrid vehicle,the selection and matching,and the energy management strategy based on considering the battery attenuation.In the course of the study,the parallel connection was selected as the PHEV powertrain connection.The main components of the PHEV system,engine,electric motor,transmission and power battery pack were selected and matched.Power batteries are continuously charged and discharged in a hybrid system,and as the number of battery cycles increases,the performance will gradually decrease.Therefore,attenuation is unavoidable.Analyzed and studied the attenuation factors of the battery,proposed the battery cycle life model and the calendar life model respectively from the theoretical point of view.After considering the battery attenuation and the design principles of the hybrid system,the precise logic energy management strategy was finally selected as the control strategy of the hybrid vehicle.AVL CRUISE was used to build a plug-in hybrid vehicle model.Then Matlab/Simulink models and implements energy management strategies.Co-simulation between the two verifies the feasibility of the energy management strategy.Based on this,combining the work characteristics of hybrid vehicles,the energy management strategy of the vehicle and the braking energy recovery control strategy are centrally realized.Simultaneously,considering the attenuation of the battery,the battery performance parameter SOC and the battery performance degradation parameter SOH during use are introduced to adjust the attenuation of the battery by adopting a strategy of dynamically adjusting the threshold value.Considering the attenuation of the battery,the battery performance parameter SOC and the parameter SOH characterizing the battery performance degradation during use are introduced into the strategy of dynamically adjusting the threshold value to adjust the attenuation of the battery to minimize the inevitable battery attenuation.The impact of battery attenuation on the vehicle’s power and economy will ultimately achieve the optimal economic efficiency of the hybrid vehicle.