【作者】 吴冀湘；

【导师】 涂光瑜；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2006， 博士

【摘要】 电力系统互联是现代电力工业发展的重要趋势,它使得区域间互相调节余缺,互相支援成为可能,但同时也带来了安全稳定方面潜在的问题,不但使系统的动态行为更加复杂,也使得局部的故障波及的范围增大,更容易发展为相继的连锁故障而造成系统的崩溃。而电力市场的推行和环保方面的制约,使得电力系统越来越运行在极限附近,使得电力系统出现安全稳定方面问题的概率大大增加。电压紧急控制是保证电压稳定防止电压崩溃的主要手段,对于电力系统的安全稳定运行有着非常重要的意义。分布式电压控制是当前电力系统电压控制的一个重要研究方向,符合无功电压控制的局域特性。本学位论文对分布式电压紧急控制进行了系统的研究,主要提出了实时电压控制分区方法,以及适用于紧急情况的多控制手段协调的分布式电压控制策略。并首次将混杂系统的理论和方法引入到电压紧急控制中,建立了基于改进微分Petri网的电压紧急控制的混杂模型。论文首选阐述了电力系统电压控制研究的意义和主要内容,回顾了电压控制研究领域的历史和现状,指出分布式电压控制是该领域的一个重要发展方向,综述了混杂系统理论的发展和取得的成果,明确了课题的研究意义和内容。然后在第二章明晰了电力系统电压紧急控制的概念和内容,从紧急控制的角度出发分析了各个电压无功控制手段并作简单比较,并在此基础上提出了分布式电压紧急控制的基本思想,在紧急情况下,实时划分控制区域,并将控制的目标由主导节点转为电压稳定性最差的危险节点。在紧急情况下电力系统的运行状态与正常状态有所不同,因此需要进行实时准确的电压控制分区,第三章提出了一种基于模糊模式识别的实时电压分区方法,可以快速准确地根据系统的运行状态确认电压分区方案,同时提出了区域中危险节点的快速确定方法。第四章在实时分区的基础上提出了分布式电压紧急控制的控制策略,该方法以分区的危险节点电压校正为目标,按照两个顺序的层次协调控制多种控制手段,一是发电机和FACTS设备等无功控制手段的协调,二是基于自适应遗传算法的低压切负荷方法,以保证电压稳定性,防止电压崩溃,同时讨论了这两种控制层次之间的协调问题。第五章首先对混杂控制系统的理论方法进行了阐述,给出了不同类型的混杂控制系统建模方法,就基于Petri网的建模进行了深入探讨,提出了改进的微分Petri网,并提出了以此为基础的混杂控制系统的建模方法。第六章从控制方法和控制手段的角度出发,分析了电压紧急控制的混杂特征,以改进微分Petri网为基础,建立了电力系统电压紧急控制的混杂模型,并进行了详细的分析。论文的最后总结了全文的工作,展望了电压紧急控制领域中的有待进一步研究的工作,提出了下一步的重点研究方向。更多还原

【Abstract】 The development tendency of modern electric industry is large-size grids connection, which makes it possible to adjust power flow among difference areas. At the same time, it could cause potential threats to the system stability. The interconnection not only makes the system dynamic characteristic more complex, but also enlarges the influence range of local fault, which makes the power system more liable to rain-failure, even collapse. Furthermore, with the popularization of electric power market and the request of environment, the power system operates close to the voltage stability limit, and the possibility of instability increases. Voltage emergency control is the major way in ensuring voltage stability and preventing collapse, which plays a very important role in the security and defense system of power system. Distributed voltage control is an important research aspect of voltage control, which meets the local essence of voltage/reactive control. This dissertation is devoted to promoting the systemic research of distributed voltage emergency control. As the chief of the dissertation, a real-time voltage control regions identification method is discussed, and then a distributed coordinated voltage control strategy based on the coordination of multi-methods used in power system urgent state is proposed, finally the hybrid model based on the improving difference Petri net of voltage emergency control is established.The dissertation firstly generalizes an overview of the history and current status of the research on power system voltage control as well as the theories and techniques of hybrid system and their applications to fields of control system and power systems. The purpose and significance of the projects is also introduced. Based on the definition of voltage emergency control and the ordinary comparison of the different voltage emergency control methods, chapter 2 proposes the ideology of distributed voltage emergency control, which identifies control region in real time and changes the control object from the pilot bus to the critical bus, i.e. the most unstable bus.In emergency state of serious contingency, the grid structure and the load status of powe system is different from the normal operating states, thereby the identification of voltage control regions should be selected according to the system status precisely. Chapter 3 presents a real-time voltage control regions identification method using the fuzzy pattern recognition to recognize the recent system operation status and selects the correspondence regions identification. It also presents a fast algorithm of the critical bus selection in this chapter. Then a distributed coordinated voltage control strategy used in power system urgent state is proposed in chapter 4, which regulates the critical bus voltage to ensure voltage stability and prevent from collapsing in two steps: first is the coordination of different reactive control methods, such as generators and FACTS units, second step is the low voltage load shedding based on self-adapting genetic algorithm.Chapter 5 gives a systemic introduction of the hybrid system theories and discusses several different hybrid modeling means, and then propose a new hybrid modeling method using the improving difference Petri net. Based on the research of chapter 5, from the point of view of control system, chapter 6 analyzes the hybrid characteristics of the distributed voltage emergency control methods from the point of control system and establishes the hybrid model of the distributed voltage emergency control in detail.At the end of this dissertation, the main results of the research are summarized. The further work is pointed out as well.更多还原