【作者】 陈静；

【导师】 孙辉；

【作者基本信息】 大连理工大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 20世纪七十年代以来,因电压失稳而导致系统瓦解的事故在国内外一些大电网多次发生,造成了长时间大面积的停电和巨大的经济损失。系统的电压崩溃往往是由某条母线或某个区域的电压失稳引起,而后扩散至整个系统,导致系统瓦解的。因此如何准确快速地防止电压崩溃并提高电压稳定性,已成为广大研究者关注的问题。本文旨于提出一种无功/电压管理的方法,为运行管理人员提供决策的信息。无功功率不能远距离传输,电压/无功是一个局部问题,因此整个电力系统电压稳定与区域无功平衡相联系。无功分层分区的管理思想要求我们把整个电力系统按照某种原则划分成若干个子区域,即进行区域划分。区域划分是协调电力系统无功/电压管理的有效手段和方法。本文首先针对现有的区域划分方法进行了深入研究,提出了具有普遍意义的电气距离法,其中,电气距离的定义和聚类分析是该方法的重点。其次应用模糊聚类电气距离法进行区域划分。对于只存在孤立节点区域的处理、如何归并PV节点以及合并各个子区域等问题,提出了相应的解决措施。最后,从各区域独立性的角度出发,通过无功裕度分析对各区域的无功/电压管理提出了建议。提出利用电压稳定指标中的切向量法确定每个区域内的电压弱节点,然后通过每个区域电压弱节点的U-Q曲线来对该节点的无功裕度进行分析,使得系统运行人员对系统的电压稳定的监控和预防侧重在电压弱节点和无功裕度最小的节点上。新英格兰10机39节点系统、IEEE-118节点系统的仿真计算结果验证了本文提出方法的有效性和合理性。更多还原

【Abstract】 Since 1970’s,system disintegration accidents caused by voltage instability have occurred many times in some big electric power systems overseas,which have caused long time large area power cut and huge economic loss.The system voltage collapses are often caused by voltage instability of some bus or some area,then proliferate to the overall system,making the system disintegrate.Therefore how to judge the system voltage stability weak nodes and weak area has become a focus problem.This paper aims to put forward a approach for reactive power and voltage management and provide information for the managers to make a decision.Reactive power can not be transmitted by the long distance,Voltage and reactive power is a local problem,thus the entire power system voltage stability is linked to the regional balance of reactive power.The idea of the reactive power stratification and district management requires us to divide the entire power system into small parts in accordance to some principle.The regional division is an effective means to coordinate the reactive power and voltage management.In this paper,we first conduct an in-depth study against the existing methods of regional division,then propose the method of the electrical distance that has the universal significance.In it,the definition of electrical distance and clustering analysis are the focus.Secondly,use the fuzzy clustering electric distance method to divide the big power system to several small parts.It deals with these questions such as isolated nodes,PV nodes and combination of sub-regions which belong to this kind of EDM.Finally from the perspective of the regional independence,give the suggestion to the reactive power and voltage management through the analysis of the reactive power margin.It uses the tangent vector method to identify the voltage weak nodes in every region,then analyze the reactive power margins of these nodes by the U-Q curves,giving the suggestion that the voltage monitoring should focus on the voltage weak nodes and the nodes that have the smallest reactive power margin.The simulink results of IEEE-39 and IEEE-118 test system verify the validity and accuracy of the method.更多还原