【作者】 谭楠；

【导师】 王宏文；

【作者基本信息】 河北工业大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 在交流调速领域中，应用最广的是变频调速技术。而作为在80年代中发展起来的高性能的新型电机调速方法，直接转矩控制在很大程度上解决了矢量控制中计算控制复杂、特性易受电动机参数变化的影响、实际性能难于达到理论分析结果的一些重大问题。但是目前该技术在低速运行时存在缺陷，本课题就此针对性地进行了一些仿真和实验的研究。 首先，本课题的研究是从异步电动机的数学模型出发，然后根据直接转矩的控制和模糊逻辑控制原理，通过实时判断磁链的区间和幅值以及转矩的大小，继而从模糊控制的电压矢量表格中选择合适的电压矢量，介绍了近似圆形磁链的理论。针对直接转矩控制系统在低速运行时依然存在的转矩脉动大、运行性能差的问题进行研究分析，结合传统的固定采样周期控制方法，提出一种基于自适应模糊转矩跟踪法，调节电压矢量占空因子，进行仿真研究，改善了系统的低速性能。 本课题还进行了实验的研究。在本控制系统的具体实现上，由于直接转矩控制对实时性要求很高，因此在硬件方面，本课题采用了目前比较流行的数字信号处理器(DSP)作为本实验的控制器，其处理速度高的特点正好符合本实验的需要；在主电路中，本系统使用了集成度高的功率器件：智能功率模块(IPM)，作为逆变环节，其集成了七个IGBT，实现了高开关频率逆变以及故障诊断的功能，从而使控制系统的体积大大缩小、控制更加灵活。更多还原

【Abstract】 In the field of AC machines control, a strategy called variable frequency control is mostly used. As a high performance and new machines control strategy developed in 1980’s, direct torque control (DTC) solves the problems that computation in vector transformation control is complex, the control characters are easily affected by the changes in machines parameters, real results of the experiments can’t achieve the level of the theoretical analysis. So now direct torque control has become an emphasis and tendency in the field of AC machines control. However DTC have some bugs at low speed. Some simulation and experiment researches about this strategy are presented in the paper.Firstly, according to the mathematical model of asynchronous machines, the principle of direct torque control and fuzzy control, the theoretical and experimental analysis about approximate round track of flux is proposed in the paper. As to approximate round track, the fuzzy method of voltage vector selection is taken. We can select the proper voltage vector by the position and magnitude of stator flux as well as the magnitude of torque. In addition, the performance criterion is respectively described, and the torque ripple at low-speed is analyzed in this paper. According to a method to adjust the duty ratio coefficient, we select a torque track with adaptation fuzzy controller to simulate. The experimental results show that the control strategy proposed can acquire better control effect.Due to the direct torque control requires very high performance of Real-time, the popular microcomputer core DSP is used as controller in the design of hardware. Its high speed of running is suitable to the experiment. In the main circuit, there is a highly integrated power element: IPM as inverter, which includes seven IGBT, has high switch frequency and fault diagnosis function. IPM greatly decreases the bulk of system. The experimental results show that this control strategy proposed can acquire better control effect.更多还原