异步电动机直接转矩控制系统研究.doc

于艳阳：异步电动机直接转矩控制系统研究 安徽工程科技学院毕业设计（论文） - PAGE 4 - - PAGE 3 - 异步电动机直接转矩控制系统研究 摘 要 直接转矩控制(Direct Torque Control, DTC)技术自问世以来，就以其新颖的控制思想、简洁明了的系统结构受到了广泛的关注并得到了迅速的发展。事实上，直接转矩控制系统利用了空间矢量的分析方法，直接在定子坐标系下计算和控制交流电动机的转矩，采用定子磁场定向，借助于离散的两点式调节(Bang-Bang控制)产生PWM信号，对逆变器的开关状态进行最佳控制，以获得高动态性能的转矩响应。 设计采用定子磁链运动轨迹近似为圆形的控制方案，通过实时计算电机转矩与磁链的误差，结合电机定子磁链的空间位置来选择相应的开关矢量。为了能够更好的，更直观的观测圆形磁链轨迹，了解直接转矩控制的特点及其所能达到的效果，本论文在对异步电动机直接转矩控制的基本原理进行充分分析的基础上，采用圆形磁链轨迹控制方法，建立了异步电动机直接转矩控制系统的MATLAB / SIMULINK软件模型，同时考虑到转矩控制在实际应用中的重要性，采用了转矩的三值调节器，以实现转矩的快速调节。 仿真实验结果表明，本文所设计的系统模型基本上是成功的，实验结果是比较令人满意的。 关键词：直接转矩控制；磁链模型；仿真；异步电动机；转矩模型  The Study of the Direct Torque Control System in Asynchronous Machine Abstract Since direct torque control (DTC) technology was invented, it has been given wide concern and has got rapid development because of its original control notion, concise system structure. In fact, the direct torque control of asynchronous machine calculates and controls directly in the stator-oriented coordinate, using the method of space vector. Adopting the stator-magnetic-field-oriented way, the signal of PWM is built by the discrete band-band adjustment in order to control the state of the switches of inverter optimally and get the optimal systems dynamic response. In the scheme of making the track of stator flux approximate circle, the relevant vector of inverter switch is selected by calculating the error of torque and flux in real time, and linking the dimensional position of stator flux. In order to observe the round track of flux better and more directly and know the trait and the effect got by DSC, the emulation model with the soft of MATLAB/SIMULINK was set up by using the method of the round flux in this thesis. In view of the importance of the torque in the practice of motor-control, the three-band adjustor was designed in order to get torque control quickly. According to the result of the emulation, the model designed in the thesis was proved correctly, and the result is satisfying. Keywords：Direc