A recent article in the Wall Street Journal, “U.S. Risks National Blackout From Small-Scale Attack,” describes work that the Federal Energy Regulatory Commission (FERC) is doing on the vulnerability of the US power grid. The most disturbing of FERC’s conclusions is that national blackouts can result from attacks on as few as only nine locations.
Research with my colleagues at the Naval Postgraduate School and our students leads me to be skeptical about the very low number of locations that FERC finds sufficient to result in systemic blackouts.
Furthermore, my research-in-progress with Yezhou Wang at The University of Texas at Austin suggests that it would likely take attacks at many more locations to precipitate a complete — as opposed to localized — blackout. This work models cascading outages that can lead to blackouts, in order to more accurately answer the questions that FERC is posing. We aim to better model the effects of failures and attacks, and we are integrating cascading outage analyses into medium- and longer-term models that consider repair times for damaged equipment. An important case-in-point is the time to replace large power transformers.
All that said, the FERC research accurately highlights the fact of the grid’s vulnerability. We need to understand and, where possible, defend the electric grid against those weaknesses.
There are sufficient fast acting protective systems to isolate defective parts of a grid and make healthy parts to continue.This requires proper Relay co ordination and selectivity.But physical damages to major equipments like Generators,Power transformers and Transmission lines will require sufficient time for restoration.There cannot be sufficient redundancy in view of cost involved.Generating stations and Major sub stations can be provided high level physical and automatic security to reduce vulnerability.But transmission lines running across long stretches of land are highly vulnerable.