X50 Electric Vehicle Motor Control Research

New energy vehicles have become the main trend of automobile development with the worsening of fuel crisis and automobile exhaust pollution.Among them,the micro pure electric vehicles are favored by the elderly and some office workers in small and mediumsized cities because they are more convenient as commuting vehicles or transportation vehicles.The motor drive system is the core of the power drive of this type of vehicle,and it is also one of the key technologies in the research of pure electric vehicle.It is particularly important to choose the appropriate motor control strategy.In this paper,the X50 micro electric vehicle developed by an enterprise is taken as the research object,and the hardware and software platform of its motor drive system is researched and designed.The main research work includes:(1)Detailed analysis of the working principle of AC asynchronous motor,using3S/2S transformation,2S/2S transformation and 2S/2S inverse transformation and other principles,deduced the mathematical model of AC asynchronous motor in the D-Q coordinate system,including the corresponding current,voltage,flux and torque equations.(2)Calculate the power parameters for the design indicators of X50 model,select the AC asynchronous motor with rated speed of 1440r/min and rated power of 4k W as the control motor of this model.(3)Through comparative analysis of the current/voltage observation model of the flux flux,on the premise of complementary shortcomings of the two models,the flux flux observation model mixed with voltage and current is selected.At the same time,Matlab2018b/Simulink software was used to model the control system,and the simulation results were found to be consistent with the theory.(4)Set up the vector control hardware platform of AC induction motor with TMS320F2808 as the main control chip,including voltage circuit module,sampling module(current,voltage,speed),protection circuit and other hardware circuit design.Texas Instruments(TI)CCStudio V3.3(Code Composer Studio V3.3)software is used to design the main program,interrupt program,detection module and SVPWM module of the control module.Vehicle trial production and dynamic performance test,the data show that the X50 motor vector control system basically meets the design requirements.