Study On The HIL For Power Transmission System Of Electric Vehicle Equipped With Electro-Mechanical Continuously Variable Transmission

Most drive system of pure electric vehicle is single or two gears reducer,while the traditional automatic transmissions,such as the AT,DCT and CVT,are rarely used in pure electric vehicle.This article will be relying on the Electronic-Mechanical Control Variable Transmission(EMCVT)researched and developed by the ChangZhou DongFeng Variable Transmission co.,LTD,as a pure electric vehicle power transmission device to study its advantage.this paper use pure electric vehicle equipped with EMCVT power transmission system as the research object,mainly includes the drive motor and power transmission gear EMCVT,and based on the LABCAR platform on the control unit to do hardware in the loop simulation test research.the main research contents are the following aspects:Studied the structure principle of drive motor and its control method.The Permanent Magnet Synchronous Motor is chosen as the pure electric vehicles driving device,and studied its control method,choose the most widely used vector control for Permanent Magnet Synchronous Motor drive speed control method,and based on the LABCAR platform to do hardware in the loop simulation test research for the vector control strategy.Studied the structure principle of EMCVT and its speed control method.In order to apply it to the pure electric vehicles,We remove the clutch mechanisms and reversing mechanisms under the original structure.For the pure electric vehicle drive motor does not need to idling start,and it can be arbitrary switching power output shaft rotation direction,you just need to keep the original speed regulation system,and the EMCVT’s control unit TCU is to control the change of the speed ratio.One of the most important point of the research is to do with TCU of hardware in the loop simulation test and verify the function and the feasibility of the control strategy.Studied the hardware in loop test system based on LABCAR platform,do in-depth understanding for the system architecture,the functions and characteristics of the software and hardware.Including the board type selection,interface to the hardware configuration,wiring harness design and the establishment of the man-machine interface of the software,configuration parameters,model import,etc..Finally,completed the building of the whole system.Studied the vehicle simulation model based on matlab/simulink.Including the driver model,battery model,motor and its control system model,the EMCVT speed regulating mechanism model,the vehicle dynamics model,and demand torque calculation model.Offline simulation is carried out for the vehicle simulation model based on matlab/simulink software,which is basis for the hardware in the loop simulation test.Finally,with the hardware in the loop simulation test of pure electric vehicle equipped with EMCVT power transmission system completed,the permanent magnet synchronous motor vector control method was verified;also Verify the EMCVT function of the control unit and control strategy;At the same time,comparing with two gears transmission,it verify that the pure electric vehicles equipped with EMCVT has an advantage on the power performance and fuel economy.