Study And Design On Permanent Magnet Synchronous Motor Control System In Electric Vehicle

Electric vehicle, which takes electrical energy as its power, has quite wide foreground because of its zero-let and non-pollution. The drive motor and its control system are hard core in the power system of electric vehicle. The control system and its intelligent control algorithm of permanent magnet synchronous motor based on DSP are researched in this thesis.The structure of electric vehicle is introduced firstly. On the basis of comparing and analyzing every kind of motor's feature, PMSM is chosen as the drive motor for electric vehicle. Then the structure feature of permanent magnet synchronous motor is analysized, and the mathematical model is established by coordinate's transformation. The vector control algorithm for PMSM is studied. The linear decoupling state equation of PMSM in d -q coordinates system is attained. After that, i_d=0 control method and flux-weaken control method are researched deeply, and then PID control algorithms of speed loop and current loop are researshed. Under Simulink environment, the simulation model of PMSM is constructed in the Matlab/Simulink.On the foundation of analyzing the vector control method, the hardware circuit of whole system has been designed. At the same time, according to the request of the electric vehicle, the circuits of speed gear, accelerator setting, detection and communication are designed. The main program and interruption service program of the system are designed by using C language and assembly language. Then the design projects and flow charts of PWM interruption service module, fault interruption service model, SCI interrupt service module and speed gear interrupt service module are given. And programs are debugged under the condition of TMS320LF2407 EVM board.Finally, intelligent control algorithms for PMSM in electric vehicle are studied, and a fuzzy self-tuning PID controller is designed. The simulation result indicates that the fuzzy self-tuning PID has quick speed response, small overshoot and good disturbance rejection ability, and it is suitable for the electric vehicle's working request.