DSP-based Design Of Vector Control System For Three Phase Induction Motor

The electric transmission technology is being faced with a history revolution now, it has become the trend that the system of AC variable-speed replaces the system of DC variable-speed and the computer digital control technology replaces the analog control technology. The system of variable-frequency and variable-speed has such a greatest future with excellent variable-speed and startup-and-stop performances, high efficiency, high power factor, less power consumption, extensive scope of application and other many merits that it is generally acknowledged at home and abroad.In this paper, the advantages and the disadvantages of the system of AC variable-speed are introduced first, as well as those of the system of DC variable-speed. At the same time, the characteristics and the application of DSP chip are introduced respectively. The purpose and the main content of this project are proposed in the dissertation. Then, according to the vector control principle, a new kind of sensorless motor speed control system based on a vector method is designed, making use of TI's advanced and fixed DSP TMS320F2806 which has the strong capability of operation. Rotor flux oriented control is adopted to realize flux and torque decoupling. With the principle of PID adaptation control, the speed and the current of the system are controlled. The rotor flux angle is calculated by means of the module of the flux estimator. Finally the angle speed is obtained by the module of the open loop speed estimator.According to the basic structure and performance of TMS320F2806 chip, the hardware design pattern and the software algorithm of the vector control for three phase induction motor are implemented. The richful peripherals of TMS320F2806 chip are fully used. The structure of the circuit is simple and the system has the strong capability to prevent from interference. The results show that the method is practical, simple and the dynamic and static performances are good.