Power Betweenness Based Identification of Power Grid Critical Links

Abstract

Synthesizing power transmission relation, topological structure and operational status of power grid a concept of power betweenness is proposed. According to network connectivity and the allocation of power transferring, the power betweenness of transmission line and that of node are defined respectively. Through the cascading attacks such as the breakage or overload on critical transmission lines, the effectiveness validation of the selected critical transmission lines is performed. Taking IEEE 39-bus system as the testing example, the power betweenness of transmission lines and that of nodes are calculated and sorted; according to sorted results, attacks are made on these elements to verify that these elements with high power betweenness are the weak links in power grid indeed. The stability verification under the static attack is performed by network efficiency function and power flow entropy respectively. Verification results show that the higher the power betweenness of electric element is, the greater the attack affects power grid operation.