Diversity of cascading failure processes in electrical grids

Investigation of the cascading failure is of great importance to understanding wide-scale power outages in electrical grids. In the current literature, researchers mainly evaluate the severity of a cascading failure process based on assessing its final damage, e.g., blackout size, to the grid. Generally speaking, the larger the final damage value is, the more severe the cascading process is. However, it is insufficient to understand the sophisticated cascading phenomenon merely from the perspective of the final damage. Cascading processes are diverse, and have multifarious features. In this paper, we focus on demonstrating the diversity of cascading processes. In particular, we exploit three important features of the cascading process, which are blackout size, system failure time and number of eruption periods. In addition, we adopt the Polish transmission system as the test benchmark, and use these three features to analyze all cascading processes triggered by N - 1 contingency on transmission lines. Finally, we find six categories of cascading processes. Our classification and discoveries can help people better understand the inherent characteristics of cascading processes and develop the ways to reduce the chances of massive blackouts.