| Definition: | unplanned sudden change in electric power system operating condition that causes widespread power quality problems or interruptions Note 1 to entry: A system disturbance can be initiated by a fault in the transmission system, a trip of a generation unit, loss of load, or any combination thereof. System disturbance can lead to abnormal ranges of frequency or voltage, loss of power system stability or cascading outages of power transmission circuits and as well widespread interruption of customer load.
|