An integrated modeling framework for cascading failure study and robustness assessment of cyber-coupled power grids

The extensive deployment of information and communication technologies significantly changes the characteristics of power grids. In this paper, we propose an integrated modeling framework for studying cascading failure and assessing the robustness of cyber-coupled power grids. By taking the perspective of cyber–physical systems, this framework depicts the electrical characteristics of the physical network, the realistic monitoring, control, and protection functions provided by the coupled cyber network, and integration with decentralized functions. It also includes a flow chart that generates a sequence of failure events in cyber-coupled power grids for simulating cascading failure. Based on the framework, a series of specific models can be constructed by incorporating concrete considerations. We demonstrate the robustness assessment of cyber-coupled power grids by one specific case study based on the modeling framework with appropriate assumptions made. Simulation results on four power test cases show that the cyber network can help effectively mitigate cascading failure and thus enhance the robustness of the grid. Moreover, the faults from the cyber layer can intensify the failure cascade and lead to a catastrophic power outage.