【作者】 李晓珺；

【导师】 白晓民；

【作者基本信息】 中国电力科学研究院 ， 电力系统及其自动化， 2010， 硕士

【摘要】 近年来,国内外相继发生了多起大规模停电事故,对人民的生产和生活造成了极大的影响,使得电网安全性问题的研究备受关注。事故发展过程中,若能快速、直观地了解当前运行点距离系统安全边界的距离,从整体上对系统的安全性做出判断,将对电网实时监控和运行状态评估具有重要的意义。安全域方法能有效解决上述问题,因此深入开展安全域方法的理论研究及实际应用,对电力系统安全运行具有重大意义。本文在深入分析电力系统静态安全域基本理论和模型的基础之上,结合电力系统的实际需要,对静态安全域的实用化数学模型以及在安全监视和分析中的应用方法进行了研究,主要工作如下：1.提出了体现系统运行风险的关键输电线路集动态搜索算法,并将其作为安全域的重点监视对象给予研究。针对传统割集断面无法充分考虑有功潮流方向和不便于处理非关键线路的问题,该方法搜索出的关键线路有效计及线路潮流裕度、线路开断对系统的影响程度以及连锁故障中潮流转移的特点,并随系统状态实时变化,更具监视和分析价值。2.针对静态安全域全域形式高维难以实际应用的问题,提出了基于系统动态分区的实用化静态安全域模型。首先根据拓扑连通关系,提出了动态分区算法,保证分区间的联络线体现系统的运行风险；然后给出了基于分区降维的静态安全域数学模型,将状态变量由节点注入功率转换为区域间的输送功率,从而将高维安全域降成三维,通过监视运行点随发电节点注入功率调整的运动轨迹,分析系统安全状况的变化趋势。3.提出了基于静态安全域的安全监视和评估方法及其可视化的实现方法。当安全域存在时,对其进行三维或二维可视化显示,并通过安全量化分析,用数值的方法求出在运行参数变化方向上系统运行点距离边界的安全裕度,突破了逐点法无法刻画电力系统整体安全性的局限,以帮助运行人员对系统安全状态做出正确判断,快速进行控制决策；当安全域不存在时,识别造成域消失的制约条件,为恢复安全域提供有用信息。4.在前述理论和方法的基础上,完成了静态安全域分析及可视化系统的软件结构设计,并介绍各个模块的具体功能及协调工作情况,最后通过对IEEE39节点系统的仿真计算,验证了所提方法的合理性以及对运行监视和评估的重要性。本论文将体现系统运行风险的关键输电线路作为安全域的重点监控对象,提出了基于系统动态分区、考虑负荷不确定性的静态安全域模型,并在三维或二维空间上实现可视化,给出系统的整体安全性测度；在此基础上,研究了基于静态安全域的电网在线安全监视和分析方法；最后提出了静态安全域分析及可视化系统的软件结构设计。该项研究在一定程度上满足了电力系统安全可观测性的要求,有助于运行人员对系统的安全状态做出正确判断。更多还原

【Abstract】 In recent years, large-scale blackouts happen in succession worldwide which brings severe consequence to the industrial production and household life. Thus, more and more attention has been paid to the research on power network security issues. In the process of failure development, a fast and visual estimation of the distance between current operating point and security boundary is favorable to the power grid real-time monitoring and evaluation. The security region method can effectively solve these problems. Therefore it is necessary to deeply research on the theory and application of the security region method, which is of great significance on improving operation security of large-scale interconnected power network.Based on the analysis of the general theory and model of steady-state security region, this thesis studies its practical mathematical model and application method on power system on-line security monitoring and analysis with the practical demand of power grid considered. The main research efforts are listed as follow:1. A novel dynamic searching method of key transmission line-set is proposed. These lines, which reflect power system operation risk, are studied as the monitoring focus of the security region. The direction of line flow can not be fully considered using the traditional cut-set, while it isn’t easy to deal with the problem of non-key transmission line. Therefore, the concept of key transmission line-set is introduced with the consideration of three factors such as line flow margin, the impact on the whole grid when line tripping and the characteristics of the transfer of power flow. These key transmission lines dynamically change with the system state, which are more favorable to the power grid real-time monitoring and evaluation.2. The whole region model of steady-state security region has a high-dimensional form that is difficult for practical application, so a practical mathematical model of steady-state security region based on dynamic division technology is presented in this dissertation. Firstly, according to the network topology, a dynamic division method is proposed, which ensures that the area tie-lines reflect power system operation risk. Then the mathematical model based on security region dimensional reduction is constructed, which reduces the model from high dimensions to three dimensions. By monitoring the pathway of the operating point with the change of node power, the trend analysis of the security state can be performed.3. The approaches of on-line security monitoring, security analysis and region visualization based on steady-state security region are proposed. The application study on steady-state security region is developed from two aspects. One is that when the security region exists, three-dimensional or two-dimensional visualization approach is proposed, and security margin between current operating point and security boundary is derived based on security quantitative analysis which breaks the limitation of point-by-point method that can not characterize the overall security of power system and helps to make the right judgments to the security state of power system. The other is that when the security region doesn’t exist, the "bottlenecks" which cause the security region to disappear is identified, which provide useful information for the restoration of the security region. 4. Based on the above theories and methods, the software architecture of steady-state security region integrated analysis and visualization system is completed. Then the specific function of each module and their coordination are described. Finally, the reasonableness and validity of the proposed methods have been proven by the test results of the IEEE39-bus testing system, which is of great significance on the on-line security monitoring and evaluation.In this dissertation, key transmission lines that reflect power system operation risk are regarded as the monitoring focus of the security region. Then the paper proposes the practical mathematical model of the steady-state security region based on dynamic division and consideration of load uncertainty and three-dimensional or two-dimensional visualization approach that gives the system overall security estimation. And the on-line security monitoring and analysis approaches based on the steady-state security are developed. Finally, the integrated analysis and visualization system software architecture design of the steady-state security region is completed. The study is to some extent to meet observability requirements for the power system security, which helps operating personnel make the right judgments to the security state of power system.更多还原