复杂电力网络中连锁故障异常现象分析与故障防御

发布时间：2018-02-09 06:32

本文关键词： 电力网络复杂网络连锁故障鲁棒性非单调增加光伏电站并网　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着发电厂、输变电站和输电线路不断扩建,以及光伏发电等新能源发电并网运行,电力系统的复杂度越来越高,少数元件或局部故障引发的连锁故障的危害也日益严重。因此,研究电力系统连锁故障机理、光伏并网对电力系统的影响以及连锁故障防御措施等关键性问题,极为必要。复杂网络理论是研究复杂电力系统连锁故障的有效方法之一,大量的基于复杂网络理论的连锁故障研究表明,网络对连锁故障的鲁棒性随容量单调增加(即：容量增加有利于网络安全)；然而本文分析结果显示复杂电力网络的鲁棒性可能随容量非单调增加(即：容量增加并非总有利于网络安全)。本文详细分析了复杂电力网络鲁棒性随容量非单调变化的本质,并根据所得结论的启发,提出了行之有效的连锁故障防御策略,最后对复杂电力网络对光伏并网的鲁棒性以及光伏并网点的选取进行了初步探索和研究。所得结论可以为光伏并网电力系统的规划和设计提供一定的参考和依据。本文的具体内容如下： 1)依托度、聚类系数、电气距离和电气介数等统计特性指标,分析了5个IEEE系统的均匀性和小世界特性,发现IEEE-145的均匀性相对其他网络较差,网络IEEE-57、IEEE-118和IEEE-145拥有小世界特性。 2)建立复杂电力网络连锁故障模型来分析网络对单一元件故障的鲁棒性,发现复杂电力网络的鲁棒性可能随容量非单调增加这一异常现象；将连锁故障分为若干阶段,通过分析每一阶段过负荷节点比例、过负荷节点的度和电气介数以及剩余负荷,发现增加的容量在连锁故障初期保护了部分节点,然而此后各阶段网络中的负荷量可能比容量增加前的多,导致更多的节点因不能承受增加的负荷而退出运行,甚至可能包括一些度或电气介数较大的关键节点,致使连锁故障规模扩大,网络的鲁棒性出现异常现象。这也说明在连锁故障初期移除少量的节点或边可以防控连锁故障。 3)提出基于电气介数的主动移除策略(Intentional Removals,IR)、主动孤岛和移除策略(Intentional Islanding and Removals,ⅡR)来防控复杂电力网络连锁故障,以网络IEEE-39和IEEE-118为例对比分析了这两个防御策略和主动孤岛策略(Intentional Islanding,Ⅱ)的功效,分析结果显示三个策略可以在故障初期有效地降低网络负荷水平,从而抑制连锁故障大规模传播,提高网络鲁棒性,其中ⅡR最优,Ⅱ次之。 4)建立光伏并网复杂电力网络模型来分析网络对光伏并网的鲁棒性,分析结果表明,如果网络容量较小,光伏电站并网运行有可能诱发连锁故障,网络对光伏并网的鲁棒性与网络的容量、光伏电站的出力和并网点等有关。进一步分析了光伏并网复杂电力网络维持正常运行所需的最小容量与并网点的特性之间的相关性,发现并网点电气介数越大,最小容量越小；电气介数相近时,并网点为传输节点时,最小容量相对较大。复杂电力网络的容量越小,所需的建设费用越低,因此,实际选择光伏电站并网点时,应该优先选择电气介数较大的节点,并从中优先选择发电节点或配电节点。
[Abstract]:With the expansion of power plants , power transmission stations and transmission lines , and the operation of new energy power generation networks , such as photovoltaic power generation , the complexity of power systems is becoming more and more serious . Therefore , it is necessary to study the linkage failure mechanism of power systems , the effects of photovoltaic grid - grid on power system and linkage failure defense measures . The complex network theory is one of the effective methods for studying the linkage failure of complex power systems . This paper analyzes the nature of the non - monotonic change of the robustness of the complex power network , and puts forward the effective linkage fault defense strategy based on the result of the obtained conclusion . Finally , the robustness of the complex power network to the PV grid and the selection of the photovoltaic grid point are studied . The conclusion can provide some reference and basis for the planning and design of the photovoltaic grid - grid power system . The concrete contents of this paper are as follows : 1 ) The uniformity and small - world characteristics of five IEEE systems are analyzed based on the statistical characteristic indexes such as degree , clustering coefficient , electric distance and electric permittivity , and it is found that IEEE - 145 has less uniformity than other networks , and IEEE - 57 , IEEE - 118 , and IEEE - 145 have small world characteristics . 2 ) establishing a complex power network chain fault model to analyze the robustness of a network to a single element fault , finding that the robustness of the complex power network can increase the abnormal phenomenon with a non - monotonic capacity ; 3 ) An active removal strategy ( IR ) , active islanding ( IR ) , active islanding and Remover ( 鈪 ) are proposed to control chain faults of complex power networks . The results show that the three strategies can effectively reduce the network load level in the early stages of the fault , so as to suppress the large scale propagation of chain faults and improve the robustness of the network . 4 ) establishing a photovoltaic grid - connected complex power network model to analyze the robustness of the network to the photovoltaic grid - connected network ;

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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