Study On Direct Torque Control Of Asynchronous Motor

As a high-performance AC speed regulation method, direct torque control has gained scholars’extensive attention for its simple control theory and excellent dynamic and static performance. In recent years, direct torque control has gained great achievements in both theory and practical applications. As the disadvantages such as great torque ripple and low performance in low speed range limit the ranges of its application, in order to improve its performance, lot’s of scholars present many methods.This paper summarizes the important and difficult issues in the direct control of the induction motor, and analysis some commonly used solutions. On the basis of previous experience, some of my own solutions are presented and analyzed.In this paper, the status of domestic and foreign research and application of direct torque control are introduced firstly, then, analyzed the basic principle of direct torque control and a minimum direct torque control system based on dual hysteresis and discrete vector is constructed. In addition, some key problems such as stator flux observe, torque ripple, speed estimation, dead time compensation and prediction control are analyzed in theory and studied by simulation, and some useful solutions are presented.A hardware platform for direct torque control of asynchronous motor based on TMS320F2812DSP is designed in order to validate the algorithms. The hardware’s key electrical circuits and composer such as rectifier, inverter and signal sampling are analyzed in this paper, ultimately, the corresponding software of algorithm are programmed in CCS platform and the flow chat and base values are presented, in addition, the algorithm of direct torque control are validated on the platform by2.2kw induction motor and obtained due effect.