P1-P4构型混合动力汽车节油率对比研究

Comparative study on fuel saving rate of P1-P4 hybrid electric vehicles

P1-P4构型混合动力汽车已成为并联式混合动力汽车的主要构型,其主要区别是电机的位置。为了研究P1-P4构型混合动力汽车节油潜力,建立了相同动力组件及车型的P1-P4构型混合动力汽车整车模型,同时搭建了基于规则、传统等效油耗最小策略(ECMS)和自适应等效油耗最小策略(A-ECMS)3种能量管理策略,在标准循环道路工况(WLTC、FTP75和HWFET)下对不同构型的混合动力汽车进行了数值仿真计算。结果表明:相比基于规则的能量管理策略,在WLTC工况下,自适应A-ECMS策略节油2.22%,对复杂工况的适应性较好;不同工况下,P1和P2构型的SOC变化趋势一致,P3和P4构型的SOC变化趋势一致;相比P2构型,不同循环工况下P1、P3和P4构型的平均节油率为4.39%、10.09%和7.57%。

Sustainable and energy-efficient consumption is the main concern in contemporary society. Driven by more stringentinternational requirements, automobile manufacturers have shifted the focus of development to new technologies such as Hybrid Electric Vehicles(HEVs). The energy management strategy controls the power flow of the whole vehicle through the control strategy and thus gives full play to the energy saving and emission reduction potential of HEVs. Equivalent consumption minimization strategy(ECMS) is an approach that reduces the global minimization problem to an instantaneous minimization problem that is solved at each moment using only parameters based on the actual energy flow in the power system. The basic principle of the ECMS approach is to allocate costs to electrical energy so that the use of electrical energy storage is equivalent to the use(or saving) of a certain amount of fuel. In recent years, the energy management strategy based on the ECMS of HEV has received much attention, but the main focus is on how to optimize the equivalence factor, and its application to different configurations is less. In this paper, we conduct a simulation study on the application of ECMS on HEVs with P1-P4 configuration to explore the fuel-saving potential of the strategy for different HEVs configurations. Firstly, the same power components are designed in the whole model of HEV with the P1-P4 configuration;Secondly, three energy management strategies based on rules, traditional ECMS and adaptive equivalent fuel consumption minimization(A-ECMS) are built, and the advantages of A-ECMS in exploring the fuel-saving potential of HEVs are demonstrated. A-ECMS is to adjust the equivalence factor through SOC deviation feedback, and this method proves to be effective in controlling the battery SOC variation within a certain range and keeping the battery SOC stable. Finally, based on A-ECMS, numerical simulations are performed for different configurations of HEVs under standard driving cycles(WLTC, FTP75, and HWFET). The results show that, firstly, compared with the rule-based and ECMS-based energy management strategies, the A-ECMS-based P2-configuration HEVs have better adaptability to complex operating conditions and the power battery operates in the high-efficiency zone, while their fuel consumption is reduced by 2.22%. Second, the comparative analysis of fuel consumption and SOC variation of different configurations shows that under standard and city driving cycles, the differences between P1 and P2 configurations are smaller and the differences between P3 and P4 configurations are smaller.Under a high-speed driving cycle, the differences between P1, P3, and P4 configurations are smaller. Third, the P3 configuration consistently has the best fuel economy when simulated with the same vehicle parameters. Compared with the P2 configuration, the average fuel consumption savings of the P1, P3, and P4 configurations under different cycle conditions are 0.94 L, 1.96 L, and 1.62 L per 100 km, with average fuel savings of 4.39%, 10.09%, and 7.57%. This study provides a theoretical basis for the configuration selection of parallel HEVs based on the ECMS.