Modeling And Design Of Power Split Hybrid Electric Vehicle Using Hierachical Topological Graph Theory

For power split hybrid electric vehicles(PS-HEV),the speed and torque are decoupled between the engine and vehicle output shaft,so it can improve the vehicular fuel economy.Based on the project of National Natural Science Foundation “Modeling and Configuration Optimization of EVT Power Split Hybrid Powertrain System Based on Graph Theory"(Project No.51575064),the following studies are carried out:(1)Based on the existing graph theory of planetary gear sets(PGS),a hierarchical topological graph theory is proposed.The adjacency matrix is introduced to realize the digital modeling of the PS-HEV powertrain system,which lays the foundation for the automated modeling of a large number of design schemes.(2)Based on the Pareto Optimal Principle and Dynamic Programming(DP),a Rapid dynamic programming algorithm(Rapid Dynamic Programming,Rapid-DP)is proposed,which guarantee the computational efficiency and accuracy.This makes it possible to evaluate fuel economy of a huge number of PS-HEV designs.(3)Combined with the Particle Swam Optimization(PSO),a joint optimization algorithm can be generated from the Rapid-DP algorithm.It can solve the powertrain parameters and component parameters optimization simultaneously.(4)Dynamic performance and fuel economy are selected as the criteria to screen the PS-HEV designs.The acceleration performance is used to characterize the dynamic performance of designs,and the fuel consumption under FTP72 or HWFET cycle is used to characterize the fuel economy of the PS-HEV designs.(5)Taken the hierarchical topological graph theory as a tool,designing a single-mode PS-HEV configuration with a single planetary gear set(PGS)is systematically solved.In addition,from the perspective of configuration mode,a systematic modeling method is proposed to solve the design problem of multi-mode PS-HEV with two planetary gear sets(PGS).(6)We give a new solution for designing the new type four-wheel-drive PS-HEV,here the hierarchical topological graph theory is extended to design the multi-mode four-wheel-drive PS-HEV,and some optimal designs of the multi-mode four-wheel drive PS-HEV with two PGS are obtained.