【作者】 梅念；

【导师】 段献忠； 李银红；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2009， 博士

【摘要】 在计算机技术和通信技术高速发展的背景下，学术界和工程界开始进行电网故障信息管理系统的探索，且近年来试点系统逐步增多。电网故障信息管理系统的作用主要在于基于二次设备信息的各项高级应用的实现。但是，目前系统的主要作用还停留在为保护专业人员分析电网故障提供原始数据，在系统采集数据的基础上尚没有形成足够的提升系统价值的应用，其实用效果难以推进系统进一步发展。鉴于此，本文致力于电网故障信息管理系统高级应用的研究，内容涉及电网故障诊断、配电网故障定位、保护动作特性分析以及保护系统的可靠性分析几个方面。目前，电网故障信息管理系统的建设还处于探索阶段，系统相关概念仍比较模糊。根据国内外电网故障信息管理系统的理论研究、实践经验和相关标准，本文对故障信息管理系统的一些基本概念进行了探讨，尝试给出了故障信息管理系统的定义，然后归纳分析了其发展的若干技术关键问题。对计及信息畸变影响的电网故障诊断分级优化方法进行了研究。首先探讨了准确及畸变开关变位信息下的停电区域搜索方法。当保护或断路器不正确动作且警报信息发生畸变时，传统的基于优化算法的电网故障诊断方法中，相似性诊断方法可能漏诊断，覆盖性诊断方法则极易误诊断。为了提高电网故障诊断的准确性，本文结合两类诊断方法的特点提出了在停电区域内进行电网故障诊断的分级优化方法。算例测试表明，所提出方法能够在畸变警报信息下快速、准确地定位多重故障，并通过状态向量的简单运算得到保护动作评价。提出了基于基本网理论的电网故障诊断方法。首先采用最大似然译码原理对监测到的信号进行信息校正，然后针对现有Petri网故障诊断模型难以准确模拟实际故障清除过程的问题，建立了基于基本网理论的故障诊断模型，并利用编码基本网理论对无畸变的信号进行故障诊断。逻辑分析和实例验证表明，所提出的基于基本网理论的故障诊断模型可准确地模拟实际的故障清除过程，且可快速地识别出故障元件、不正确动作的保护和断路器以及畸变信息。提出了基于过热区域搜索的多电源复杂配电网的故障定位方法。该方法通过在过热弧搜索方法中定义支接点处的负荷及对最小配电区域进行故障定位，使其可以适用于含特殊开关接线的多电源网络。在此基础上，针对其简化算法——矩阵算法，给出了一种较简洁的多电源配电网多重故障定位的统一判据。同时，分别针对故障信息不完备和信息畸变的情况，为两种算法给出了相应的应用方法。借鉴交流保护动作特性的分析方法，对HVDC系统中阀短路保护和高压电容器不平衡保护的动作特性进行了研究。HVDC工程中获得较广泛应用的两类阀短路保护的动作方程存在一定的差异。本文通过研究阀短路保护测量的电流在各种换流器故障下的变化规律，对两类动作方程进行了对比分析。然后，对其中的一类动作方程进行了改进，使其具备定位故障桥的功能。分析了已有阀短路保护制动函数的缺陷，提出了一种分段式制动函数，较好地克服了制动函数灵敏性和选择性之间的矛盾。HVDC工程中的高压电容器通常采用H形接线或分支接线形式。对单个支路电容器的故障发展过程中以及两个支路电容器均有电容元件击穿时的不平衡电流及相应的过电压倍数进行了定量推导。分别针对两种接线形式的电容器，分析了其不平衡保护的动作特性。最后，以高压直流输电工程中的阀短路保护系统为例，利用成功流法对各种冗余配置下整个保护系统的可靠性进行了分析。根据系统误动率(拒动率)分别随测量装置和保护装置的误动率(拒动率)变化的曲线，得出了直流保护系统的一些可靠性规律。更多还原

【Abstract】 With the rapid development of computer and communication technology,the academicand the engineering community began the exploration on fault information managementsystem of power systems(FIMS).In recent years,the number of trial systems is on agradual rise.The function of FIMS lies in the advanced applications based on data acquiredfrom the secondary equipments in power systems.However,the main role of FIMS now isserving raw data for dispatchers to analyze faults in power systems.There are not enoughadvanced applications to raise the value of the system,which prevents the system fromfurther development.Thus,this paper makes a detailed study on the advanced applicationsof FIMS,such as fault section estimation in power systems,fault location in distributionnetworks,analysis on the operational characteristics of protections,as well as the reliabilityanalysis of protections.Currently,the construction of FIMS is still in the process of exploration and therelevant concepts are vague.According to the theoretical studies,the operationalexperiences and the related standards,this paper makes a discussion on the concepts indetails.First the definition of FIMS is given,and it is followed by the analysis of some keytechnical problems for its further advancement.A gradual-optimization based approach for fault section estimation in power systemsunder aberrant information is proposed.First,methods to search for outage areas under bothaccurate and aberrant alarm of breaker-position change are presented respectively.For thetraditional optimization-based methods,the diagnostic methods based on similarityprinciple may omit some faulty sections whereas the parsimonious covering principle basedmethods may regard normal sections as faulty ones.To improve the correctness of thediagnostic methods,a gradual-optimization based diagnostic method is proposed,whichcombines the features of the above two types of methods.Case studies show that themethod proposed can quickly locate the correct multiple faulty sections in theabove-mentioned scenarios,and can make an evaluation of protection operations by simplecalculation of some state vectors.Furthermore,a new diagnostic method grounded on elementary net theory is presented.First,the maximum likelihood decoding theory is adopted to correct the aberrated alarm.Toovercome the drawbacks of traditional models based on Petri nets,a new diagnostic modelbased on the elementary net is built.Then correct alarms are fed into the new model tocarry out the diagnosis process.Logical analysis and case studies show that the model built can accurately simulate the practical fault clearing process,and can make a quick andaccurate estimation of the faulty sections,misoperated protections and breakers as well asthe aberrant alarm.To locate the faults in complex multi-source distribution networks,a new methodbased on over-heated area searching is proposed.By defining the load on the vertices withmultiple branches and locating the minimum distribution area in the over-heated arcmethod,the method can be easily used in the multi-source distribution networks withspecial switches.Then,measures are given for its use under aberrant alarms.Based on thenew method,a concise unified criterion for fault location in complex multi-sourcedistribution networks for its simple version,matrix algorithm,is proposed,followed by themeasures when alarms become aberrant.Borrowing methods to analyze operational characteristics of AC protections,those ofvalve short-circuit protections and unbalance protections for high-voltage(HV)capacitorsin high voltage direct current(HVDC)transmission systems are studied.There are somedifferences between the two types of valve short-circuit protections which are commonlyadopted in HVDC systems.By analyzing the variational rules of the relational currents ofthe protections,the performances of the two operational equations are compared.Then,oneof them is revised so that it can locate the faulty bridge.To coordinate the contradictionrequirements of selectivity and sensitivity in protection settings,a setting function isproposed according to the analysis of existent setting functions.High voltage capacitors inHVDC projects are H-connected or branch-connected.The ratio of the unbalance current tothe filter current and the over voltage are calculated during the evolution of the inner faultboth in a single capacitor branch and in multiple capacitor branches.Based on the study,operational characteristics of HV capacitor unbalance protections are studied.Finally,take the valve short-circuit protection in HVDC projects as an example,reliability of the whole protection system under different redundant configurations isanalyzed with Goal Oriented methodology.Some rules on HVDC protections are obtainedby observing the waveforms which depict the rate of unwanted trip and the rate of failure totrip of the whole protection system changes with those of the protection equipments and themeasurement equipments,respectively.更多还原