【作者】 张亚刚；

【导师】 王增平；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2011， 博士

【摘要】 新型广域后备保护系统中最关键的问题是快速准确的故障元件定位。适应于新型广域后备保护的故障定位方法,依靠的数据是由WAMS提供的电压电流同步向量等信息。故障定位在快速性上要求必须在后备保护动作所需的延时之前完成,并留出足够的时间用以调整相关保护定值。本文对基于WAMS的电力系统故障元件定位方法进行了深入的分析和研究,主要的工作包括：(1)根据复杂电力系统不同的故障类型,提出了一种系统故障的聚类分析定位方案。主要采用模糊聚类分析和系统聚类分析等理论方法,对系统故障所导致变化的电气量进行了归类分析,并有效地解决了广域后备保护系统中快速界定故障区域的问题。(2)在聚类分析快速界定故障区域的基础上,提出了一种电力系统故障元件定位的模式识别方法,主要利用模式识别理论中的模式分类技术和判别分析原理来研究系统故障所导致的电气量显著变化的内在统计规律。针对对称和不对称短路故障时出现的相序电压电流等电气量,采用模式分类技术和判别分析原理能够及时、准确的定位故障元件,进而为故障隔离奠定基础。(3)基于主成分分析理论,本文提出了两种利用PMU实时量测信息的电力系统故障特征提取方案,即主成分节点系数方案和主成分节点得分方案。其中,主成分节点系数方案能够通过对节点系数的分析得到故障特征：即故障元件对应着主成分系数的最大变量。而在主成分节点得分方案中,系统故障一般对应着主成分的最大得分变量,这两种方案均可以独立的进行故障定位。基于主成分分析理论的故障元件定位算法,具有很强的抗干扰能力,并能够满足系统冗余性的要求。(4)从理论和应用两个层面对非线性复杂动力学系统进行了深入广泛地研究。探索性地利用上述理论对电力系统正常运行与故障状态所具有的动力学特征进行了讨论和分析。针对广域测量系统中PMU实时量测信息的符号动力学分析结果,本文提出通过计算Lyapunov指数来实现准确、快速的确定故障位置。经过计算,在电力系统故障情况下,实际的故障位置往往靠近具有最大Lyapunov指数的位置,并且离故障点越近,对应的Lyapunov指数相对较大。该结论可能对应着电力系统的一个固有的本质属性。更多还原

【Abstract】 The key issue of novel wide area backup protection has been concentrated on the rapidly and accurately fault component location. The location method used in this novel backup protection system is mainly relying on the voltage and current synchro-phasors provided by the Wide Area Measurement System, WAMS. Obviously, the faulted component should be determined as soon as possible, which must not exceed the limit of time delay in design principle of backup protection. And then, it is the rest of time that is enough to adjust the setting of related protections. In this paper, the research of novel faulted component location method based on WAMS will be the focus, on which a lot attention has been put. The main contents of this thesis contain:(1) According to different types of fault in complex electric power system, a cluster analysis based fault location scheme has been provided. In this method, fuzzy cluster analysis and hierarchical cluster analysis and so on are used to classify the changes of electrical quantities from system failure. Finally, fault component location and fault section partition are realized accurately and effectively.(2) A pattern recognition based method for fault location in complex electric power system is proposed. The pattern classification technique and discriminant analysis principle in pattern recognition theory are utilized to study the inherent law of electrical quantities’ marked changes from system failure. The simulation results indicate that respectively study on the phase or sequence voltage and current in unsymmetrical faults and symmetrical short circuit faults, the pattern classification technology and linear discrimination principle are able to rapidly and accurately identify the fault components and fault sections.(3) Based on principal components analysis theory, two fault feature extraction schemes are formed by real-time measurement information of PMU in complex electric power systems, namely, fault feature extraction scheme based on node coefficient in principal components and fault feature extraction scheme based on node score of principal component. According to "Scheme A:node coefficient", by analyzing node coefficient, the fault is usually corresponding to the variable with the biggest coefficient in principal component. According to "Scheme B:node score", the fault is usually related to the node with the biggest principal component score. In a summary, both of these two schemes are able to carry through fault detection independently and effectively.(4) We have thoroughly studied nonlinear complex dynamical system from the layers of theory and application. In order to quickly and accurately locate faults in complex power grids, many explorative researches have been initiated by means of symbolic dynamics. According to the symbolic dynamics analytical results of PMU real-time measurement information from WAMS, we have advanced exact and quick fault localization by computing Lyapunov exponent. The studies indicated that the actual fault position is usually near the position with the biggest Lyapunov exponent during fault circumstance in complex electric power systems. Generally, the nearer to the fault position, the bigger Lyapunov exponent is. The obtainment of this conclusion may represent an inherent and essential attribute of electric power system.更多还原