On Sat, Mar 14, 2015 at 07:32:22PM -0400, Lennart Sorensen wrote:
Some very big interconnects disconnected due to overloading. This left the grid in three isolated parts, one with over supply, one with under supply and one that was pretty well balanced on its own.
It was all triggered by a misconfigured main link where one end had different limits configured than the other end, so one end thought shutting down a parallel line would be fine, but the other end tripped due to misconfigured limits for the line, which then dropped all the load on yet other lines, which then tripped, and bye bye grid. Fortunately it only took about 45 minutes to restore everything.
If interested, read this: http://nuclearpoweryesplease.org/blog/2008/12/13/the-day-wind-power-nearly-b... -- Len Sorensen