考虑级联故障的电力系统综合脆弱性评估

发布时间：2018-06-18 13:11

本文选题：电力系统 + 结构脆弱性　；参考：《北京交通大学》2014年硕士论文

【摘要】：大规模电力系统在带来巨大经济利益的同时,潜在风险也较之前更有威胁。近年来国内外电力系统的大停电事故,多由级联故障而非单一故障引起。传统稳定性分析已不能保证电网的安全有效运行,电力系统的脆弱性引起了国内外学者的广泛关注,针对大电网薄弱环节的脆弱性评估近些年来则成为了一个研究热点。在广泛收集国内外相关文献的基础上,给出了电力系统脆弱性的一个描述性定义,对其进行了合理分类,将其分为结构脆弱性、状态脆弱性和综合脆弱性,并深入分析了国内外的研究现状。介绍了级联故障的表现形式,基于复杂网络理论,采用事故链模型对级联故障进行描述。结果表明,以事故链模型分析级联故障,符合大停电发生的物理特征和实际过程。在结构脆弱性评估方面,介绍了图论中图、树、最小生成树等的概念,对求最小生成树的克鲁斯卡尔算法做出了改进,并应用于电力网络的结构分析,引出了“最小潮流树”的概念,从而为大型复杂系统网络结构的定量分析开辟了一条新的途径。在此基础上,从有功功率的区域平衡和传输距离两方面,对电力系统整体结构的脆弱性进行了综合评估。在状态脆弱性评估方面,综合考虑了母线电压的稳定裕度及变化率、和线路的传输功率,采用局部参数的连续潮流法求出母线的PV曲线,用来分析母线的静态电压稳定情况及临界电压。基于归一化的思想,分别构建了母线电压状态指标和线路功率越限指标,并将二者结合以综合反映系统的状态脆弱性。基于风险评估理论,考虑了级联故障的发生概率,结合结构脆弱性和状态脆弱性指标,对级联故障下的系统脆弱性进行综合评估,并以此为基础评估了各条线路的脆弱性,以确定系统的关键线路。以IEEE-24RTS系统为例,分别分析了系统在正常运行、N-1故障、N-2故障状况下的情况,并指出了系统中的关键线路,验证了本文所提方法的正确性和有效性。
[Abstract]:At the same time, the potential risks of large power systems are more dangerous than before. In recent years, power outages at home and abroad are mostly caused by cascading faults rather than single faults. Traditional stability analysis can not guarantee the safe and effective operation of power grid. The vulnerability of power system has attracted wide attention from domestic and foreign scholars. In recent years, vulnerability assessment for weak links of large power grid has become a research hotspot. A descriptive definition of power system vulnerability is given on the basis of extensive collection of relevant literature at home and abroad. It is classified into structural vulnerability, state vulnerability and comprehensive vulnerability. The present situation of research at home and abroad is also analyzed. The representation of cascaded faults is introduced. Based on the theory of complex network, the fault chain model is used to describe the cascaded faults. The results show that the analysis of cascaded faults by accident chain model accords with the physical characteristics and actual process of blackout. In the aspect of structural vulnerability assessment, the concepts of graph, tree and minimal spanning tree in graph theory are introduced. The Cruskar algorithm for finding the minimum spanning tree is improved and applied to the structural analysis of power network. The concept of "minimum power flow tree" is introduced, which opens a new way for quantitative analysis of large complex system network structure. On this basis, the fragility of the overall structure of the power system is comprehensively evaluated from the two aspects of active power regional balance and transmission distance. In the aspect of state vulnerability assessment, considering the stability margin and change rate of bus voltage and transmission power of line, the PV curve of bus is obtained by continuous power flow method with local parameters. Used to analyze the static voltage stability and critical voltage of busbar. Based on the idea of normalization, the busbar voltage state index and the line power overrun index are constructed, and the two indexes are combined to reflect the state fragility of the system. Based on the theory of risk assessment, considering the probability of cascaded faults and combining structural vulnerability and state vulnerability index, the vulnerability of cascaded system is comprehensively evaluated, and the vulnerability of each line is evaluated based on the risk assessment theory. To determine the key circuit of the system. Taking IEEE-24RTS system as an example, this paper analyzes the situation of the system under the condition of normal operation of N-1 fault and N-2 fault, points out the key circuit of the system, and verifies the correctness and validity of the method proposed in this paper.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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