基于改进节点电气介数的电网关键节点辨识

摘要

To improve the operation safety level of power system,an identification method of key nodes in power grid is put forward based on improved node electric betweenness. On the basis of the power sensitivity matrix between line pow?er variable and nodal injection power variable,the improved node electric betweenness is calculated to identify key nodes according to the different types of nodes. Considering the load loss caused by node removal and the weighted pow?er distribution entropy with node injection power disturbance,node importance index is defined to measure the node function during the load power supply and power transmission,which is further used to verify the identification results of key nodes. With simple calculation,the improved node electric betweenness overcomes the shortcomings of the tradi?tional indexes which assume that the power goes along the shortest path between nodes,and it also considers the direc?tion of power flow. The simulation in IEEE 39-node system shows that the improved node electric betweenness can effec?tively identify the key nodes during the load power supply and power transmission.%为提高电力系统运行安全水平,提出一种基于改进节点电气介数的电网关键节点辨识方法.以线路功率变量与节点注入功率变量之间的功率灵敏度矩阵为基础,结合节点类型的不同,计算改进节点电气介数识别电网的关键节点.综合考虑节点移除造成的负荷损失和节点受到注入功率扰动时的电网加权潮流分布熵,定义节点重要性指标衡量节点在负荷供电和功率传输中的作用,对关键节点识别结果进行检验.改进节点电气介数计算简单,克服了以往方法中假设节点间功率按最短路径传输的不足,同时考虑了线路中潮流的方向性.在IEEE39节点系统中对该方法进行验证,结果表明利用改进节点电气介数可有效识别电网负荷供电和功率传输中的关键节点.