考虑节点的桥重要度的城市电网结构脆弱性分析

Structural Vulnerability Analysis of Urban Power Grid Based on Bridge Importance of Nodes

电网中存在某些具备"桥"特征的节点,此类节点连通若干重要的分区,但因其自身节点度数较低,往往不易被识别。为了分析电网结构脆弱性,本文定义了节点的桥重要度,该指标综合考虑节点度数和所连接线路的相对重要程度,解决了当节点度数相同时无法判断相对重要程度的问题。同时,仅需网络的局部结构信息即可判断出其中更重要的"桥节点"。以天津电网2018年冬季运行方式为例,进行电网结构脆弱性分析。仿真结果表明所提出的桥重要度比节点度数、介数等拓扑特征指标,更能反映出电网结构上的薄弱环节,特别是能够辨识出电力输送通道上关键的桥节点,对电网规划及运行具有指导意义。

In a power grid,there exist some bridge nodes that connect several important partitions. However,they are often difficult to identify because of their low degree centrality. To analyze the structural vulnerability of power grid,the bridge importance of node is defined in this paper. This index comprehensively takes into account the degree centrality and the relative importance of connected lines,thus solving the problem that the relative importance of nodes cannot be judged when their values of degree centrality are equal. At the same time,only the local structural information of network is needed to judge the bridge nodes of higher importance. The operation mode of Tianjin power grid in the winter of2018 is taken as an example,and its structural vulnerability analysis is carried out. Simulation results show that compared with the topological characteristic indexes such as degree centrality and betweenness centrality,the proposed index of bridge importance can better reflect the weak links in the power grid structure. In particular,it can identify the key bridge nodes in the power transmission channel,providing guidance for the planning and operation of power grid.