Efficiency And Its Optimization Study For Electro-mechanical Transmission System

In the increasingly serious energy crisis today,HEV has become the focus of research.Efficiency as a mechanical and electrical composite transmission system is an important content of vehicles,for the power flow optimization,the design of the drive system and provide reference for the formulation of the optimal control strategy.Establish a general transmission efficiency of integrated model and its optimization model is of great significance.We first establish the efficiency model of various key parts,in order to ensure the efficiency of versatility and precision of the model,Willans lines model method is adopted to establish the efficiency of engine,motor model.Set up the efficiency of planetary mechanism model with a simple and accurate method;Establish the efficiency of battery considering the battery SOC,charge and discharge power and temperature;Considering the influence of high speed centrifugal force and temperature,clutch/brake belt line loss model is set up;More accurate theoretical calculation instead of experience value is adopted to establish the efficiency of fixed axis gear.With different structures(series,parallel and hybrid)as the research object,combined with the engine,motor,gear mechanism and battery efficiency and other key components model,established unified efficiency mathematical model by analyzing the power flow characteristics.Hybrid as the important research object,mainly analysis the different topological structures of electric power division characteristics,and established the mathematical model of general efficiency under different topology structure.To test the coupling efficiency of institutions of the model and the efficiency of each variable with the change rule,set up a dual mode electromechanical compound drive system integrated test platform.The results strongly proves the correctness and efficiency of model efficiency changing with the main variables.With the help of MATLAB optimization toolbox,establish the comprehensive efficiency of mechanical electronic transmission system optimization model,and develop the efficiency of the optimized process.By analysis of several typical working conditions of efficiency optimization results,get the efficiency advantages,the optimal operating point of the engine and the motor,also received the efficiency with variation of coupling ratio and battery power,can provide reference for the optimal control strategy formulation.