Postmortems

India 2012 grid failures (700 million affected)

Wikipedia says:

The 30 July 2012 blackout affected over 400 million people and was briefly the largest power outage in history by number of people affected. The blackout on 31 July is the largest power outage in history. The outage affected more than 620 million people, about 9% of the world population.

There’s an official postmortem here (pdf) with this summary:

The underlying causes and the suggested measures to reduce the probability of re-occurrence of such grid disturbances are discussed. A number of issues have been thrown up by the recent grid disturbances and these include the following:
a) Skewed load generation balance across Regional grids
b) Grid indiscipline including overdrawals and under drawals
c) Depleted reliability margins
d) Failure of defense mechanisms
e) Absence of primary response from generators
f) Insufficient visibility and situational awareness at Load Despatch Centers
g) Inadequate appreciation of transfer capability vis-à-vis transmission capacity
h) Inadequate dynamic reactive reserves
i) Performance of the Protection Systems
j) Impediments to the speedy restoration of the systems
k) Distortions arising from the existing Regulations on grant of connectivity
l) Excessive reliance on unscheduled interchange rather than organized electricity markets
m) Tightening of the stipulated range for grid frequency
n) Institutional issues

via Dan Luu’s collaborative postmortem collection, contribution by Anirudh Ramesh