Energy Management Strategy Of Power Split Hybrid Powertrain Based On Double Rotor Motor

The power split hybrid powertrain can take into account the advantages of series and parallel hybrid powertrain,and the planetary gear and torque-speed regulating motor can realize the two-dimensional flexible adjustment of the engine running point,so that the fuel consumption of the vehicle can be signif icantly reduced.From the point of view of electrical and mechanical ports,the compound structure of planetary gear and engine speed regulating motor is equivalent to that of double-rotor motor.The power split powertrain based on double rotor motor can realize the unification of intensity and reliability.In this paper,a state of charge sustaining power split powertrain based on a dual-rotor motor dynamic coupling device is studied,and the energy distribution strategy of the proposed configuration is analyzed from both global and instantaneous perspectives.Firstly,the configuration and operation mode of power split hybrid powertrain are studied based on double rotor motor.According to the connection mode of the mechanical ports of the double-rotor motor,the configurations were divided into equivalent single-mode input,output and compound split hybrid systems,and the dynamic equilibrium equations of the three configurations were derived according to the lever method.The power transfer efficiency and power split ratio of three different configurations are studied.Finally,based on the given w orking conditions,the equivalent two-mode single-row input split configuration is quantitatively analyzed by comparing the efficient velocity domain ratio of the above configuration.Secondly,based on the selected configuration,the vehicle parameter mat ching and dynamic programming global energy management algorithm are studied.According to the dynamic economy index of the vehicle,the power matching relationship of each power component was analyzed and a numerical interpolation model was built based on the measured data.To solve the dimensional disaster problem of dynamic programming algorithm,a rapid optimization strategy based on the optimal efficiency line of the engine is proposed.According to the dynamic characteristics of the proposed configuration,the optimization objective equation was established.The optimization effect of the proposed algorithm on fuel economy of the system is verified by backward simulation model.The characteristic parameters of the power coupling mechanism were optimized by the rapid dynamic programming algorithm,and the value selection scheme was given in combination with the fuel economic index.Thirdly,In this part,through the Pontryagin’s minimum principle,a discrete point traversal algorithm within the engine feasible region is constru cted.The convergence relationship between the common-state variables and the algorithm is analyzed theoretically and the optimization objective equation is construct ed.The optimization effect of the algorithm is analyzed through specific working conditions.Power exponent and tangent penalty terms are introduced for SOC lower than the limit value,and the correction effect is verified.Finally,based on the proposed algorithm,the influence of the efficiency domain variation of the dual-rotor and torque regulating motor on the fuel economy performance of the system is studied,and the conclusions are given.Finally,the real-time energy optimization algorithm of equivalent fuel consumption minimization strategy is studied online.The steady expression of oil-electricity equivalent factor sequence set is derived.The equivalence between this algorithm and Pontryagin minima algorithm is proved,and the off-line solution strategy of oil-electricity equivalence factor is given.The feasibility domain constraint set and the construction of Hamiltonian minimization of the algorithm are analyzed.The forward simulation model is used to verify the speed following and fuel economy.Last but not least,the real-time correction effect of the power consumption penalty term on SOC is studied and a comparative analysis is given.