Dsp-based Direct Torque Control System

Induction motor is been used everywhere in industry. The improving of the automatic technology in industry brings the stricter requirement to the motor control system. To certain extent, whether the development of motor control system can keep up with the pace of the industrialization will affect the whole domestic economy.The highest precision, shortest response time and simplest computing are the eternal destination of motor control system. Direct Torque Control (DTC) was been brought based on these objects by western country -Germany. Nowadays, it has become the most important control theory in induction motor control system just because of its characteristics such as simple computing, low reliability to motor parameter and good dynamic and statistic characteristic. Single-chip microcomputer and conventional strategy such as vector control still makes up the internal induction motor control system for the present. Nevertheless, with the applying of new technologies such as fuzzy control and sensorless, there has much more data should be calculated and much more requirement for precision and real time, under such situation, the single-chip microcomputer shows more and more deficiencies. Consequently, it is very necessary to develop a new system which combine a newer microcomputer and DTC strategy.The paper illustrate all the control theories of induction motor in detail, and design a DTC system via digital signal processor(DSP). The system use TMS320LF2407A DSP chip which is specialized in motor control system, the chip contains many special module for motor control, and decrease many peripheral instruments. The newest Intelligent Power Module (IPM) is been used for power instrument, its inner protect circuit raise reliability of the system. The utilization of IPM and DSP merge the newest theory and instrument. The hardware system is indeed an universal one, it can make up all kinds of induction motor control system if configuring corresponding software. The software of the system is developed through embedding Assemble Language in C program, such method takes the system readable and transplantable characters. Then, the author not only analyze the result of experiment, but also testify the system via Simulink module of Matlab software. Finally, the paper sum up the insufficiency of whole system and predict the directionofDTC as well.Altogether, the whole DTC system with hardware and software has been designed in the paper. And it was been proven that the system indeed has higher precision and better dynamic and statistic characteristic.