【作者】 胡超芳；

【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， 2003， 硕士

【摘要】 在交流调速领域中，应用最广的是变频调速技术。继1971年矢量变换控制技术出现之后，交流传动技术就从理论上解决了交流调速系统在静、动态性能上与直流传动相比所存在的问题。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，直接转矩控制又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。因此目前该技术已成为交流调速传动中的一个热点，本文就是针对这一技术进行了一些仿真和实验的研究。 首先，本文的研究是从异步电动机的数学模型出发，然后根据传统直接转矩的控制原理，对于定子磁链的不同轨迹，分别进行了六边形和圆形磁链的理论和实验分析。在六边形磁链的研究中，本文主要是使用了施密特触发器，通过磁链自控制单元来实现的；而对于圆形磁链的直接转矩而言，则是利用了电压矢量查表的方法，通过实时判断磁链的区间和幅值、以及转矩的大小，继而从表格中选择合适的电压矢量。总之，在这两种方法中，无论是利用哪一种来实现，最终都是要实现电压矢量的合理输出。此外，本文还对这两种控制方法中性能指标的特点分别进行了说明，并且对在低速下的转矩脉动进行了分析、比较。 本文不仅进行了理论及仿真的分析，而且还着重进行了实验的研究证明。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，采用了目前比较流行的数字信号处理器(DSP)作为系统的控制器，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。实验结果表明，在有速度反馈时本文提出的控制方法能取得较好的控制效果。更多还原

【Abstract】 In the field of AC machines control, a strategy called variable frequency control is mostly used. After vector transformation control is presented, the AC machines control technology can theoretically solve the problem on the static and dynamic performance relative to the DC technology. As a high performance and new machines control strategy developed in 1980’s, direct torque control 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 in the field of AC machines control. Some simulation and experiment researches about this strategy are presented in the paper.Firstly, according to the mathematical model of asynchronous machines and the principle of direct torque control, the theoretical and experimental analysis about hexagon and round track of flux is proposed in the paper. In the researches about hexagon track, SMITH triggers are used, so is flux self-control. As to round track, the 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 sum, both of these two algorithms are realized through selecting proper voltage vector. In addition, the performance criterion are respectively described, and the torque ripple under low-speed is analyzed and compared in this paper.Not only the theoretical and simulating analysis is carried out, but also experimental research. Because 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 for 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