Vector Control System Of Asynchronous Motor Based On TMS320F2808

Three-phase AC asynchronous motor is in great demand in various industrial applications. The speed control technology of AC motor has also been an important issue in the field of electric drive. Asynchronous motor has a simple structure. It is inexpensive and has a more and more superior performance with the development of power devices and vector control or other advanced methods. To achieve high-precision speed, rotor-field oriented vector control system is studied. The rotor flux and torque are controlled separately. Besides, system has a stable and fast response with the use of speed-current double loop.In the aspect of control algorithm, this paper presents a flux method combining current model and voltage model by variable coefficient of weight. It makes the two methods work in the low and high speed respectively, which can also transit smoothly so that system can estimate rotor flux in a wider speed range accurately. The thinking has been tested by SIMULINK. The detection of motor speed also uses the same idea.In the aspect of software programming, paper chooses TI's latest high-performance fixed-point TMS320F2808 as the core controller. Its powerful computing capabilities have brought great convenience to operations. The structure of software uses a hierarchical and modular design and debugging system. C language with Q-format is used and IQmath functions are involved. CCStudio v3.3 is used for real-time simulation and debugging. The whole software part has a compact structure and high efficiency. It is easy to read and modify.In the aspect of hardware design, the smallest system of DSP is used as the control module. Then speed optical encoding, current and voltage detection and switch read circuits are designed around it; IPM is selected as power module and driving and protection circuit is designed for it; In addition, multiple isolated power supplies are designed for the security of electricity supply.In the end, the paper offers lab facilities and data results. The results show that double-loop speed sensorless vector control system provides accurate speed detection, harmonic distortion, good dynamic performance, high accuracy and good ability of anti-interference of voltage and load. Especially, due to the use of powerful TMS320F2808 with small size and high ability, the whole real-time system is cost-effective needing less peripheral circuit.