The Research On TMS320F2812-based SVPWM Control System Of Asynchronous Motor

In recent years, the development in power electronics manufacturing technology, microcomputer technology and modern motor control theory greatly promotes the development of AC variable frequency speed regulation technology. By using Space Vector Pulse Width Modulation(SVPWM) technique, three-phase asynchronous motor can achieve high speed regulation performances which are comparable to DC motor, and its SVPWM control system has higher accuracy, faster response speed and larger range while regulating the speed of three-phase asynchronous motor. The SVPWM technique is deeply studied in this paper, then a TMS320F2812-based SVPWM control system of three-phase asynchronous motor is designed, and lastly the performances of this control system were tested and evaluated by simulation and experiments.Firstly, the squirrel cage asynchronous motor is selected as research object and then the basic mathematical models of three-phase asynchronous motor in static three-phase coordinate system, static two-phase coordinate system and rotating coordinate system are analyzed by means of coordinate transformation theory. And the vector control technique which is based on rotor flux orientation is used to realize the decoupling of excitation component and torque component of stator current in three-phase asynchronous motor. The voltage space vector control technique algorithm and its implementation method are analyzed, and at last the double closed loop vector control system of three-phase asynchronous motor is designed.Secondly, the vector control system model based on rotor flux orientation of three-phase asynchronous motor is built in Matlab/Simulink environment. This model includes blocks such as three-phase asynchronous motor, coordinate transformation, rotor flux observer, PI controller and SVPWM. Then the starting performance and variable speed running while loading of this motor are analyzed.Based on the SVPWM control principle of three-phase asynchronous motor, hardware and software of SVPWM control system based on DSP TMS320F2812are designed. The hardware design includes main circuit, detection circuits and auxiliary circuits. The software design includes main program, interrupt program of timer(T1),speed sample program, PI program, and SVPWM waveform generation program. Control program is developed by using IDE(Integrated Development Environment) CCS3.3. Finally, experiment waveforms are recorded and analyzed, and the effectiveness of designed system is verified. At the same time, analysis of the problems occurred in experiments lay necessary foundation for further research.