Characteristics Analysis And Simulation Study On Hydro-Mechanical And Electric Transmission System Of Passenger Car

Based on the hydro-mechanical transmission(HMT),a small power motor is used as a power supplement source to design a hydro-mechanical and electric transmission(HMET)for cars.The system not only has the advantages of adjustable speed and high mechanical transmission efficiency of transmission,but also can use electric drive hydraulic system(ET)to achieve energy and energy recovery in vehicle starting and driving.The car equipped with HMET system can make the engine work in the optimal condition,and can improve the vehicle emission performance and fuel economy.Because of the use of small power motors,the number of batteries required is less,so the price is cheaper than the hybrid electric vehicle on the market.In this paper,the following aspects are studied and discussed:(1)By consulting the data,the development of the mixed vehicle is briefly introduced,and the challenges facing the mixed vehicle are pointed out.Based on this,the concept of HMET is put forward.In view of HMT system,the transmission theory is deeply researched,and the comparison and selection of the merging schemes of the electric drive system are made.(2)According to the performance requirements of the car,the parameters of the transmission of the target vehicle are matched and calculated.After the engine is selected,the appropriate transmission device is selected for the HMT system,including the selection of the hydraulic pump,the motor and the determination of the displacement.According to the electric drive hydraulic system ET,the components of the system are selected and the parameters are calculated.Finally,a complete set of HMET system transmission scheme is designed and determined.(3)Based on the Matlab/Simulink software,the mathematical model of the vehicle transmission system is set up,and several typical working conditions are modeled and simulated.Two driving modes are modeled and simulated for the best power and the best economy.The simulation results verify the design requirements.(4)Based on the design requirements of the HMT system,we completed the design of the internal shunt HMT system experimental device,and described the experimental process,and completed the design of the experimental data record form.