Instruction manual
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AQ G3x7 Generator protection IED
174 (211
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The report generated includes the duration and the minimum value. A voltage swell is
detected if any of the three phase-to-
phase voltages increases to a value above the “Swell
limit” setting. In this state, the binary output “Swell” signal is activated. The signal resets if
all of the three phase-to-
phase voltages fall below the “Swell limit”, or if the set time
“Maximum duration” elapses. If the voltage returns to normal state after the “Minimum
duration” and before the time “Maximum duration” elapses, then the “Swell Counter”
increments by 1, indicating a short-time voltage variation.
The report generated includes the duration and the maximum value. A voltage interruption
is detected if all three phase-to-
phase voltages fall to a value below the “Interruption Limit”
setting. In this state, the bin
ary output “Interruption” is activated. The signal resets if any of
the three phase-to-
phase voltages rises above the “Interruption limit”, or if the time
“Maximum duration” elapses. No counter is assigned to this state.
The inputs of the sag and swell detection function are:
•
RMS values of the of three phase-to-phase voltages,
•
Binary input
•
Setting parameters
The outputs of the sag and swell detection function are:
•
Sag detection
•
Swell detection
•
Interruption detection
•
Counters
NOTE: if all three phase-to-
phase voltages do not fall below the specified “Interruption Limit”
value, then the event is classified as “sag” but the reported minimum value is set to zero. The
sag and swell detection algorithm measures the duration of the short-time voltage variation.
The last variation is displayed.
