Powertrain Configuration Analysis And Energy Optimization Of Heavy-Duty Hybrid Electric Vehicle

Heavy-duty trucks have become the main force in road transport dut to their efficient transportation capacity and low transportation costs.However,due to long travel mileage and high fuel consumption,energy-saving and emission reduction of heavy-duty trucks have received much attention,and researching its energy-saving and emission reduction technologies is of great significance for reducing China’s oil consumption and greenhouse gas emission.Hybrid electric powertrain technology has been highly valued domestic and overseas and is regarded as the future development direction of heavy-duty trucks,due to its low cost,long driving range,low fuel consumption and low emission.Based on the national key R&D project of “Super energy-saving heavy-duty truck hybrid electric system development research”,this paper focuses on analysis of configuration and energy optimization,and carries out the analysis and optimization of hybrid electric vehicle powertrain system,energy management strategy design and optimization,one pedal regenerative braking strategy design and optimization.A simulation model is constructed in this paper for three hybrid systems suitable for heavy-duty trucks from the perspective of vehicle economy,including powertrain system component models(motor model,engine model and battery model),vehicle dynamics model,vehicle controller model and driver model.With the goal of fuel economy and vehicle operating costs(including fuel cost and battery degradationcost),the global optimization algorithm is used to optimize and select the battery capacity.Through the global optimization of the energy distribution problem of hybrid electric systems,a realtime energy management strategy based on global optimization is proposed.The strategy improves vehicle fuel economy by at least 18.44%.Combining the above research work,a total cost of ownership model for heavy-duty hybrid vehicles is established to analyze the cost of each configurations under different economic scenarios.The control simplicity,initial cost,investment payback period,total cost and fuel economy of each configureations are compared.In order to reduce the fuel consumption of the vehicle and improve the efficiency of regenerative braking energy,this paper proposes a one pedal regenerative braking energy strategy.Firstly,based on the actual road travel data,the acceleration-sliding control strategy is studied,and then the sliding control design based on vehicle speed and accelerator pedal is proposed.Finally,according to the principle of motor braking principle,the optimal braking force distribution of the motor under one pedal regenerative braking energy control is proposed.Compared to the traditional regenerative brake energy strategy,the one-pedal braking energy regeneration strategy can reduce the power consumption by 3.70%.A test bench for the hybrid electric system is established,and a bench test of the energy optimization algorithm is carried out.The experimental results show that the bias of the simulation results and test results of the real-time energy management strategy proposed in this paper is only 1.52%,and the algorithm has good validity.The one-pedal braking energy regeneration strategy can achieve 66.67% regenerative efficiency in the test.In the joint experiment of energy optimization algorithm,the fuel consumption of the heavy-duty hybrid electric vehicle is 11.20L/100 km.