Causes of the August 14th Blackout in the United States and Canada
Investigation Report into the Loss of Supply Incident affecting parts of South London at 18:20 on Thursday, 28 August 2003
Summary (excerpt from the above report of the August 14th blackout)
The Causes of the Blackout
The initiation of the August 14, 2003, blackout was caused by deficiencies in
- specific practices,
- equipment, and
- human decisions that coincided that afternoon.
There were three groups of causes:
Group 1: Inadequate situational awareness at FirstEnergy Corporation (FE). In particular:
A) FE failed to ensure the security of its transmission system after significant unforeseen contingencies because it did not use an effective contingency analysis capability on a routine basis.
B) FE lacked procedures to ensure that their operators were continually aware of the functional state of their critical monitoring tools.
C) FE lacked procedures to test effectively the functional state of these tools after repairs were made.
D) FE did not have additional monitoring tools for high-level visualization of the status of their transmission system to facilitate its operators' understanding of transmission system conditions after the failure of their primary monitoring/alarming systems.
Group 2: FE failed to manage adequately tree growth in its transmission rights-of-way. This failure was the common cause of the outage of
three FE 345-kV transmission lines.
Group 3: Failure of the interconnected grid's reliability organizations to provide effective diagnostic support. In particular:
A) MISO did not have real-time data from Dayton Power and Light's Stuart-Atlanta 345-kV line incorporated into its state estimator (a syste monitoring tool). This precluded MISO from becoming aware of FE's system problems earlier and providing diagnostic assistance to FE.
B) MISO's reliability coordinators were using non-real-time data to support real-time flowgate monitoring. This prevented MISO from detecting an N-1 security violation in FE's system and from assisting FE in necessary relief actions.
C) MISO lacked an effective means of identifying the location and significance of transmission line breaker operations reported by their Energy Management System (EMS). Such information would have enabled MISO operators to become aware earlier of important line outages.
D) PJM and MISO lacked joint procedures or guidelines on when and how to coordinate a security limit violation observed by one of them in the other's area due to a contingency near their common boundary.