Parameters Matching And Optimization Of An Electro-mechanical Transmission For Its Straight Running Characteristics

In the increasingly serious energy crisis today,electric transmission technology has become the research focus.In this paper concerning power split electro-mechanical transmission(EMT),static and dynamic matching and optimization are studied.The optimal boundary values of EMT can be obtained by static matching.Dynamic matching will optimize the working area of components like engine and motors,improving the EMT performance.In the aspect of static matching,the engine cannot exert the peak torque if the parameters of motors are not matched well in a power split EMT.The influence of different motor parameters on the EMT performance,especially the relation of motor working points and that of the engine is studied with the help of the analysis on EMT performance.Subsequently,a novel strategy for the motor parameters matching with the optimal power output characteristics as objective for the EMT is proposed.The matching method is validated by matching examples,based on which the static matching performance evaluation system is constructed.Based on the Isight-Matlab software platforms,an multi-objective optimization model is built with the minimum power of motors as objective,using NSGA-II optimization algorithm.The result comparison shows that the MGA peak power is 10.4% less and the MGB peak power is 6.9% less than before,while the dynamic factor increases by 20.9% and the acceleration time increases by 11%.Finally,the steady-state analysis is realized as a software by using the Matlab/GUI program.In the aspect of dynamic matching,a dynamic matching model,a dynamic matching performance evaluation system and a military driving cycle are developed based on the Matlab software platforms,Simdriveline and Simpowersystem,using the rule-based categorization strategy.The EMT performance under various driving cycles is obtained through the simulation of the dynamic model under various driving cycles.The conception of matching physical parameters and control parameters is proposed.The dynamic matching and optimization process based on the Isight-Matlab software platforms is also proposed.Sensitivity of the design parameters for dynamic matching performance are analyzed by Design of Experiments(DOE).A multi-objective optimization model is built to improve the motor energy utilization ratio and equivalent fuel consumption through optimizing the design parameters.Finally,the feasible region of the design parameters where the dynamic matching model can get the optimal evaluation index is obtained.