Design And Analysis With Power Split Mechanism Of Plug-in Hybrid Electric Vehicle

As one of the key components of plug-in hybrid electric vehicle(PHEV),the method to design power split mechanism which is more and more concerned by scholars.Planetary gear mechanism with two degrees of freedom which can couple speed and torque of engine and motor.Therefore,it is gradually being used to design power split mechanism.This dissertation relies on the national new energy automobile industry technological innovation project,and a novel power split mechanism with single motor and single planetary gearset is proposed.It is analyzed with the finite element and dynamic analysis.The main conclusions of this dissertation are summarized as following:Firstly,the advantages and disadvantages of three kinds power split modes of power split mechanism are compared and analyzed.Based on this analysis,the input power split modes of power split mechanism is designed in this paper.By controlling of clutch and brake,which can achieve ten working modes and satisfy the required working modes of PHEV.At the same time,based on the equivalent principle of leverage method,the working modes of power split mechanism are analyzed.Secondly,on the basis of the automotive parameters and performance indexes of PHEV,the parameters of integrated starter generator motor,engine and lithium-ion battery pack of PHEV are designed.Meanwhile,based on the results of these parameters of the main power components,the main parameters of each component of power split mechanism are determined.In terms of the obtained parameters,three-dimensional model of power split mechanism which is established by using CATIA software.Finally,according to the established three-dimensional model of power split mechanism,the finite element analysis(FEA)of the power split mechanism which is completed based on HyperWorks software.Through static analysis,the maximum dedendum bending stress of the power split mechanism is less than the allowable bending stress,which indicates that the power split mechanism can meet the working requirements.According to modal analysis,the first ten modes frequencies of the power split mechanism are obtained.From the simulation results,it can be concluded that the power split mechanism can avoid resonance damage with external excitation frequencies.And the dynamics of the power split mechanism are simulated based on Adams software.The results showed that the power split mechanism meets the requirement of kinematic relationship,and the meshing force presents the characteristic of periodic change.