步电动机，具有结构简单、制造容易、价格便宜、坚固耐用、运行可靠、很少维修、使用环境及结构发展不受限制等优点，在工、农、国防等诸多领域得到了广泛的应用。直接转矩控制是上世纪80年代继矢量控制之后的又一新型高性能交流异步电机控制技术。它是直接对电机转矩进行控制，解决了矢量控制计算复杂、特性易受电机参数变化影响等问题。 本文研究了异步电动机直接转矩控制的方法原理，在分析交流异步电动机数学模型的基础上，详细阐述了电压空间矢量、磁链和转矩的直接控制等直接转矩控制的基本理论，介绍了整个系统的结构框架，最后给出了定子磁链运行区间的判断方法和区段电压的选择方法与逆变器的开关表。 通过MATLAB/SIMULINK对整个控制系统进行了仿真，得到系统各项参数的仿真结果，从仿真结果来看，使定子磁链轨迹成圆形，定子电流波形成正弦波，定子电流波形、磁链波形、变化平稳，转矩波形脉动较小。为了更好的控制电动机，直接转矩控制系统的磁链、转矩控制器采用滞环调节控制，速度控制器采用了PI调节器，达到了很好的调速效果。 硬件部分详细介绍了以DSP TMS320F2812为核心的控制电路，以及以MOSFET为核心的主电路，其中主电路设计包括逆变器及其驱动电路的设计，以及外围电路的设计。设计并实现了整个系统的软件功能，控制系统软件利用CCS2.2环境下的C语言编程，完成系统各功能子函数。实验结果表明系统设计合理，电机运行稳定可靠。

The asynchronous motor with a simple structure, to create easy, inexpensive, sturdy and durable, reliable, very little maintenance, the use of the environment and the structure of the advantages of unrestricted development in the engineering, agriculture, national defense and many other fields a wide range of applications. Direct Torque Control is the last century, following the 80's after the vector control of another new high-performance AC motor control technology. It is the direct control of motor torque to address the computational complexity of the vector control, electrical characteristics of the vulnerability of the impact of problem parameters. In this paper, the asynchronous motor direct torque control method of the principle of exchange of the analysis of mathematical model of asynchronous motor based on the detailed voltage space vector, flux linkage and torque, such as the direct control of direct torque control of the basic theory, introduction the structure of the whole system framework, and finally give the stator flux running between the judge and select the section voltage and inverter switching table. Through the MATLAB/SIMULINK control system for the entire simulation, the parameters of the system simulation results, simulation results from the point of view, so that the stator flux trajectory into a circular, stator current, flux changes in a smooth waveform, in order to better control motor, direct torque control system of flux and torque hysteresis controller regulating the use of control, speed controller using the PI regulator to achieve a good speed results. Hardware details of a DSP TMS320F2812 as the core control circuit, and MOSFET as the core of the main circuit, as well as the design of peripheral circuits. Designed and implemented the entire system software, control system software CCS2.2 environment using C language programming of the complete system functionality Functions. The experimental results show that a reasonable system design, the electrical operation of stable and reliable.