Identification Of Vulnerable Lines And Vulnerable Nodes In Power Grid Based On Complex Network Theory

Along with the rapid development of economic, regional and even transnational interconnected power system has become the inevitable trend of the development of power grid. The power network has gradually joined the ranks of the world's most complex man-made networks. Large scale interconnection of power network can make the power transmission to thousands of miles away, but it also increases the possibility of fast transmission of local fault to large area or the whole network. Currently vulnerable research of power grid is not uncommon. Viewing the point of research, although existing research examine power system brittle weak in different perspectives, the influenced power grid vulnerability factor is numerous and existing studies tend to have not been carefully thought out which cause differences between study results and the real situation. Moreover, the existing research focused on the research on the identification of vulnerable lines, and the research about identification of vulnerable nodes is relatively small. Respectively for lines and nodes, this paper proceeding the existing research, proposed vulnerable line identification of grid based on comprehensive betweenness and vulnerable nodes identification method based on comprehensive classification.The vulnerable line identification method based on comprehensive betweenness consider running state from the aspect of the power transfer relationship and the tidal margin. Meanwhile, the method analyse the impact of power grid vulnerability caused by relay protection, offset of node voltage, geographical position of line and other factors. The paper proposed the concept of comprehensive betweenness combining with the topological structure of power grid. Comprehensive index can be more realistic to identify the vulnerability of the power grid. Finally, the efficiency of the proposed method is verified by the transmission efficiency of the wire breakage.The nodes is divided into power nodes and load nodes (contact nodes in this column) in node identification method based on classification, and the vulnerability identification indexes of different nodes are formulated according to their respective characteristics. In research of different vulnerable nodes, it not only considers the vulnerability of node caused by relay protection, but also considers the power transmission status of the node to the whole network from two aspects, which are the active global effect of the node and the local influence index of reactive power in node analysis of the role of the entire network respectively. Finally, considering the overall vulnerability of the node, it also records the influence of the node's own factors on the vulnerability of the node. In this paper, the accuracy and practicality of the proposed method are verified by the IEEE39 node system.