【作者】 王博；

【导师】 尹项根； 游大海；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2011， 博士

【摘要】 大面积停电事件是社会各界始终关注的问题,但如何解决这一问题却使人们困惑。因为随着我国电力系统的不断发展,现有方法无法涉及的一些因素不断成为可能导致电力系统发生大面积停电的原因,这些因素往往不在人们的预想之中。2008年的中国南方冰灾使我国南方电力系统受到了严重的破坏,这使得我国政府部门开始意识到电力系统现有的控制手段虽然能够维持系统的稳定,但是还不能完全有效的控制大面积停电的风险水平。因此要解决大面积停电风险的控制问题就需要发挥政府的优势,让政府和电力企业进行合作来加强对电力的监管以及制定降低电力系统大面积停电风险的措施。传统的电力系统安全运行分析方法主要基于由元件物理模型组成的系统模型,并局限于系统本身运行的稳定破坏情况,较少考虑自然灾害以及人为因素对系统安全运行的影响。基于现代风险理论的安全风险评估方法则考虑了影响电力系统安全运行的各种因素,将安全风险评估和脆弱性分析方法相结合可以使得对电力系统安全评估既有全面性,也有重点性。为此,需要开展电力系统安全风险及脆弱性评估可行性研究和框架研究工作,论证电力系统安全风险及脆弱性评估工作的必要性,进行电力系统安全风险及脆弱性评估指标体系的探索和研究。本文首先基于复杂性科学研究方法,运用综合集成方法中的多方合作思想,提出多方合作的电力系统安全风险评估基本框架。该评估框架以整体性为原则,主要由数据信息体系、评估指标体系、评估专家体系、多方合作评估体系四个方面构成。基于该框架所建立的评估体系可以充分发挥多方合作解决开放复杂巨系统问题的优势,充分发挥政府部门的统筹协调优势,发挥电力企业、科研院校以及与电力系统安全相关的社会其他部门的专家在专业技术方面的特长,同时该框架以一种操作性强的评估流程为核心来完成对复杂电力系统的安全风险评估,评估结果可以为电力企业制定有针对性的措施提供指导,同时也为政府监管电力安全提供依据,从而有效的降低复杂电力系统中长期风险。本文接下来从系统论角度出发提出了一套复杂电力系统安全风险评估指标体系和计算方法。该指标体系模型采用事故树建模技术建立,可以充分考虑系统在结构、技术、设备等方面的各种影响因素。指标权重的计算方面,本文采用改进的层次分析法计算,该方法具有较强的实用性和可操作性,同时可以充分利用专家经验提高权重计算的客观性和准确性,并可用于多方合作的电力系统安全风险评估中。本文通过指标算例验证了评估算法的有效性。本文还从防止大面积停电的角度给出了复杂电力系统的脆弱性定义,并利用信息集合理论建立了复杂电力系统脆弱性四层集合模型,该模型利将复杂电力系统海量数据信息划分为状态信息、缺陷状态信息、可能引起停电的缺陷状态信息和脆弱性信息四类集合,并描述了针对电力系统的各种攻击手段与集合之间的关系。根据四层集合模型,本文基于信息熵理论和关联聚类方法,利用复杂电力系统的信息源建立了一套具有客观性、实用性、适应性的脆弱性评估指标体系和评估方法用于求取四层模型中的脆弱性信息集合。所提出的脆弱性评估方法能够充分利用复杂电力系统的各种数据源,挖掘与脆弱性有关的信息,通过对实际国内某省级电力系统的试评估验证了评估方法的可行性和有效性。最后本文从整体性、实用性、可操作性出发,将安全风险评估与脆弱性分析方法相结合提出一套复杂电力系统安全性综合评估方法,使评估结果既可以反映系统的宏观风险,又可以反映系统微观方面的薄弱环节,从而可以更加全面的评估系统的中长期安全性。本文利用该体系对贵州省电力系统的进行了试评估,得出的评估结果符合系统的实际情况,同时本文根据评估结果提出了具体的改进对策,为电力企业制定降低风险和脆弱性的措施提供了很好的参考。更多还原

【Abstract】 Large-area Power Outages is always of concern to all sectors of society. However, how to prevent Large-area Power Outages makes people confused. With the expansion of China’s power system, there are more and more factors, which contribute to Large-area Power Outages and are unconsidered by existing methods. These factors are often not expected among people. The snow disaster that hit Southern China in 2008 caused serious damages to southern power systems, which made Chinese government realize that the exiting methods could maintain statability of power system, though they cannot control the risk involved in power system effectively. Therefore, Chinese government should play to there strength, and it’s necessary to collaborate with power enterprises in strengthening Electricity Regulation and taking countermeasures to reduce the risk of Large-area Power Outages.Traditional analysis methods of power system security are based on the system model which consists of the physical models of the component in power system. And the methods are considered more about the instability factors of the system operation, but fewer factors of the natural disaster and human.The methods based on modern risk theory consider most of the factors which could impact the security of the power system. They combine the security risk assessment and vulnerability analysis method to make a comprehensive and focused power system security assessment. Therefore, we either need to research the feasibility, necessity and framework for power system security risk and vulnerability assessment, or research indicator system of them.This paper first proposes a framework of the multi-cooperation power system security risk assessment, which is based on the complexity science research methods and the ideology of the multi-cooperation from the Comprehensive Integrated Method. The proposed framework consists of four parts, which are data information system, assessment indicator system, experts system, multi-cooperation assessment system. And the principle of the proposed framework is integrity. Based on the framework, this paper establishes an assessment system which can give full play to its advantages of multi-cooperation to resolve the issue open complex giant system, and advantages of integrated and coordinated government departments, and advantages of professional and technical expertise of experts in power enterprises, research institutions and other sectors of society related to the power system security. Meanwhile, using the workable assessment process of the framework to complete the complex power system risk assessment could provide suggestions to develop targeted measures to reduce the medium and long term risk of complex power systems for electric power companies. And it also provides the basis to monitor the electrical security for the government.Based on the systematology, both complex power system security risk assessment indicator system and algorithm method are proposed. The indicator system established by the fault tree modeling technique, we can fully consider various factors which impact the power system in the structure, technology, equipment and other aspects. We calculate the weights of the indicators by using the improved Analytic Hierarchy Process, which has strong practicability and maneuverability. The proposed method could take advantage of experts’expertise and be used in the multi-cooperation power system security risk assessment. Then a numerical example has been given to prove the effectiveness of the method.This paper gives a definition to the vulnerability of complex power system from the point of avoiding LPO, and constructs a four-layer set model of complex power system, which divides the large body of data information of complex power system into four sets (status information, defect condition, the defect status that might cause power failure, and vulnerability) and describes the correlation between the means of attack and the sets. Then based on these correlations, this paper constructs a set of objective, practical, and adaptive index assessment systems and evaluation methods, taking advantage of the information sources of the complex power system. The assessment results could reflect the current vulnerable points in complex power system; provide information of important reference value for the operation and planning of the electricity sector. The assessment results of a provincial large power grid in China validate the correctness and the effectiveness of the proposed method.Finally, from integral, practical and operational points of view, this paper proposes an integrated power system security assessment method, which combine the security risk assessment and vulnerability analysis method. The assessment results of the proposed method could reflect both the risk in macro level, but also weaknesses in the micro level, and it could assessment the medium and long term security of power system more comprehensive. An assessment example of Guizhou provincial power system is given and the assessment results are consistent with the real situation of the tested system. This paper also provides specific measures for improvement, which could be good references for developing measures to reduce the risk and vulnerability of the power system by power enterprise.更多还原