Research On AT Matching Design And Shift Control Of Pure Electric Vehicle

With the continuous development of pure electric vehicle technology,more and more pure electric vehicles have entered the market and entered people's daily life.Because of the motor's work peculiarity have some special advantages,the transmission of electric vehicles almost use the reducer.Although it also can meet the normal driving demand,but it has some disadvantages such as reduc ing the power and increasing the energy consume of pure electric vehicles.And we must encounter the situations that the vehicle is lack of the power,when we are driving in uphill a long way or we are driving fast.With the increase of people's the level of material demand,the pure electric vehicle just has a one gears reducer for shifting can't meet people's needs.So we can predict that the electric vehicle equipped with multi-speed transmission will become the future trend of development.In this paper,we choose the high-end electric MPV as the research object.So its power transmission system should be selected and matched,system's parameters should be designed and calculated.We should set up the appropriate shift schedule,and we set up the dynamics simulation model of the vehicle based on Matlab/Simulink software to analyze and verify its feasibility,in order to meeting the needs of the power,economy and comfort.We select the power transmission system of electric vehicles,finally chose the traditional power transmission system arrangement,the permanent magnet synchronous motor as the driving motor,AT as the automatic transmission in system;analyzed the characteristics of the motor and calculated in turn necessary parameter of driving electric machine and AT mechanical transmission part.Finally,the rationality of the designed powertrain is verified.The original characteristics and working characteristics of torque converter are analyzed,and the locking torque converter is adopted.Based on the analysis and introduction,we formulated the matching principle of the motor and the torque converter,and the two was matched.We obtained their work area,furthermore,the common output characteristics of the motor and torque converter are obtained.Finally the common characteristics of the motor and torque converter are analyzed and verify,and compared the power without the hydraulic torque converter.Introduced the current types of shift schedule,their advantages and disadvantages were analyzed to determine the selection of two parameter shift schedule as the shift schedule.Together with the output characteristics of the motor and the torque converter,we made the best power and the best economic shift rule,and due to the analysis of their own needs,making the shift law of comprehensive of both the two parameters.In the Matlab/Simulink software,the simulation model of power transmission system was established,and the model was simulated,compared the power of power transmission system between whether have the use of a torque converter,verified the power transmission system of pure electric vehicle AT rationality and the advantages,and compared the result of simulation of the three shifts.