Line Hardening Strategies for Resilient Power Systems Considering Cyber-Topology Interdependence

Line hardening applied before extreme events is one of the most effective resilience enhancement strategies in power systems. As traditional power systems are evolving into cyber–physical power systems composed of physical power grids and communication networks, both transmission lines and communication cables should be protected. However, existing strategies mainly focus on hardening transmission lines. In this paper, a trilevel optimization model is proposed to synergistically harden both transmission lines and communication cables. Considering the wide application of optical fiber composite overhead ground wire (OPGW) cables, the cyber-topology interdependence is firstly analyzed. Furthermore, a main-alternative-emergency routing model is proposed between one control center and communication nodes in power systems. Finally, the trilevel optimization-based line hardening model is constructed, which is solved by the column-and-constraint generation(C&CG) algorithm. Case studies are performed on the 24-bus IEEE reliability test system and IEEE 57-bus system. Numerical results validate that the performance of hardening strategies is heavily affected by the cyber-topology interdependence according to comparing with the traditional hardening models. This paper highlights the importance of communication networks on the resilience enhancement of power systems.