Coordinated attacks against substations and transmission lines in power grids

Vulnerability analysis on the power grid has been widely conducted from the substation-only and transmission-line-only perspectives. In order words, it is considered that attacks can occur on substations or transmission lines separately. In this paper, we naturally extend existing two perspectives and introduce the joint-substation-transmission-line´s perspective, which means attacks can concurrently occur on substations and transmission lines. Vulnerabilities are referred to as these multiple-component combinations that can yield large damage to the power grid. One such combination consists of substations, transmission lines, or both. The new perspective is promising to discover more power grid vulnerabilities. In particular, we conduct the vulnerability analysis on the IEEE 39 bus system. Compared with known substation-only/transmission-line-only vulnerabilities, joint-substation-transmission-line vulnerabilities account for the largest percentage. Referring to three-component vulnerabilities, for instance, joint-substation-transmission-line vulnerabilities account for 76.06%; substation-only and transmission-line-only vulnerabilities account for 10.96% and 12.98%, respectively. In addition, we adopt two existing metrics, degree and load, to study the joint-substation-transmission-line attack strategy. Generally speaking, the joint-substation-transmission-line attack strategy based on the load metric has better attack performance than comparison schemes.