August 2003 blackout - interesting insight

There is an interesting insight into the August 13, 2003 blackout at Knowledge Problem. This event, which dropped most of the East Coast into darkness, was caused by a simple failure and this failure caused a number of neighboring systems to cascade and shut down. What would have happened if they were able to disconnect from their neighbors and become islands... bq. One way of making the grid work better is to figure out how it can fall apart more gracefully. The ability of a subregion to cut itself off from the surrounding grid � islanding � can help limit the cascading failures that constitute wide-spread blackouts. This was one of the lessons drawn from the 1965 blackout. bq. But islanding can cause problems of its own, too, if not done well. If the subregion that separates is itself not already in approximate balance between generation and load, it may fail anyway. In addition, the system left behind by the islanders may become more difficult to manage. bq. If you follow the details of the cascade in Chapter 6 of the Task Force final report, you learn that at 4:10:39 PM tripping of protective relays isolated Cleveland and Toledo from the rest of the grid. The island was unstable because there was insufficient generation inside the island, the island dropped load but couldn�t stabilize and blacked out. At the same time, Detroit suddenly had a lot of excess power because the Cleveland and Toledo load separated from the system, and this excess power bounced back through the system tripping additional relays and leading to the separation of much of the Northeastern U.S. and Eastern Canada from the rest of the Eastern interconnection. bq. On the other hand, most of New England and the Maritimes separated from the rest of the grid and kept operating, as did small regions in New York, Ontario, and Quebec. The official report on the blackout can be found here (6.8MB PDF)