Long-Term Effect of the n-1 Criterion on Cascading Line Outages in an Evolving Power Transmission Grid

Cascading transmission line outages contribute to widespread blackouts. Engineers respond to the risk of cascading line outages by applying policies such as the n-1 criterion and upgrading lines involved in recent cascading outages. The transmission grid slowly evolves as these policies are applied to maintain reliability while the load grows. We suggest how to assess the long-term effect of these policies on the risk of cascading line outages by simulating both the cascading and the slow evolution of the transmission grid. The long-term effects of these policies on the probability distribution of outage size and the grid utilization are computed for the IEEE 118-bus test system. The results show complex system self-organization of an evolving transmission grid.