Cascading

The uncontrolled successive loss of System Elements triggered by an incident

Cascading

The uncontrolled successive loss of System Elements triggered by an incident at any location. Cascading results in widespread electric service interruption that cannot be restrained from sequentially spreading beyond an area predetermined by studies.

Note:

• This version is approved by FERC on 1/21/2016.
• Another version of the term “Cascading” was approved by FERC on 3/16/2007 and became inactive on 6/30/2016.
• The term “Cascading Outages” was remanded by FERC on 12/27/2007.

Cascading Outage by IEEE

A cascading outage is a sequence of events in which an initial disturbance, or a set of disturbances, triggers a sequence of one or more dependent component outages:

• In some cases they halt before the sequence results in the interruption of electricity service
• In many case, cascading outages have resulted in massive disruptions to electricity service: Northeast blackouts in 1965 and 2003, New York City blackout in 1977, two WECC blackouts in 1996, Brazil blackout in 2009, WECC blackout in 2011, etc