A Novel Design Methodology For Fixed-axle Hybrid Coupling Architecture With A Single Electric Motor

Clean energy and electrification are the main development direction of the a automobile industry.The hybrid electrical vehicle(HEV)which has two different driving systems,internal combustion engine(ICE)and electric motor(EM),is the best excessive technology.There are many architectures of HEV.Such as series HEV,parallel HEV,series-parallel HEV and power-split(PS)HEV.The power from ICE and EM can be coupling in different architectures and the operation models are generated by the combination of different ICE and EM working statues.The potential of fuel economy is exerted by various hybrid architectures.Therefore,the novel design methodology for HEV architecture is the key to improve the comprehensive performance.How to find the most optimal design methodology in specific architecture is the research hotpots.The fixed-axle powertrain of HEV as the design object has the benefits of simple configuration,better technology inheritance and easy to control.The various positions of EM have different characteristics in ixed-axle powertrain of HEV.This paper proposed a novel design methodology for fixed-axle hybrid coupling architecture with a single electric motor.The design methodology is based on Equivalent Tree Graph Methodology(ETGM),which is first applied in planetary gear sets(PGs)architecture.The Multi-Position X(MPX)architecture is also proposed to achieve multiple PX hybrid architecture characteristics.The research is sponsored by Chongqing Excellent Talent in University Support Project,Chongqing Jiaotong University Graduate Research and Innovation(Innovation Fund)Project and conducts the following research:It has been summarized the extensively researched design methodologies in HEV coupling architecture.The principle of different design methodologies is analyzed.Based on ETGM,the characteristics of fixed-axle architecture is stated and the correspondence between tree graph and architecture.A novel design methodology for fixed-axle hybrid coupling architecture with a single electric motor is proposed by ETGM.The tree graph can be seemed as the combination of trunk,branch and leaf.As the design object is fixed-axle architecture of HEV,the trunk is corresponding to shaft,the branch is corresponding to input or output components,the leaf is corresponding to model switching components.The definition of architecture that need to be designed can generate trunk.The G matrix is used to described the connection of shaft and input or output components.The trunk-brank structure can be generated automatically by Matlab.After setting constraints,the needful 3-node trunk-brank structure can be obtained from the screening.If the multiple PX hybrid architecture characteristics models need to be achieved,the corresponding design constraints should be considered.As the trunk-branch graph is obtained,all possible placement of mode switching components should be founded.While using the constraints,the random combination of different mode switching components placement can generate different effective matrixes.These leaves(mode switching components matrix)are combinate with trunk-branch graph to obtain tree graph.The various operation status of input or output components and mode switching components are filled in J matrix.Matlab would search every possible power line by Depth First Search(DFS)and Binary Search Tree.The search includes basic operation models and multiple PX hybrid architecture characteristics(models).Finally,the relevant components of the tree graph are embodied to generate a schematic diagram of the devised architecture.Based on the same method,the design of the 4-node tree graph is derived.The modeling of M-PX is built in Amesim and the control strategy is built in Matlab/Simulink.The WLTC is chosen as testing cycle.It is compared that the fuel economy and power performance about P2,P3 architecture and M-PX architecture.Then the conclusion is proposed and the design,validation process is finished.