Modeling Cascading Failures in the North American Power Grid

The North American power grid, one of the most complex technological networks in existence, permits long-distance power transmission as well as disturbance propagation. We model the grid using its actual topology and incorporate plausible assumptions about transmission substation load and overload. Our results indicate that a solitary substation loss can induce an overload cascade and reduce the grid's transmission efficiency by 25{\%}. Examining the damage inflicted by single node removals, we find three universal behaviors which suggest that 40{\%} of the transmission substations can induce an overload cascade when perturbed. While significant damage can result from a single node removal, subsequent removals have only incremental effects, which agree with the power grid's topological resilience to less than 1{\%} node loss.