Instruction manual
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AQ G3x7 Generator protection IED
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In the figure below. is presented the structure of the instantaneous overcurrent algorithm.
Figure 12: Structure of the instantaneous overcurrent algorithm.
The algorithm generates a trip command without additional time delay based on the Fourier
components of the phase currents or peak values of the phase currents in case if the user
set pick-up value is exceeded. The operation of the function is phase wise and it allows
each phase to be tripped separately. Standard operation is three poles.
The function includes a blocking signal input which can be configured by user from either
IED internal binary signals or IED binary inputs through the programmable logic.
Table 3-14 Setting parameters of the instantaneous overcurrent protection function
Parameter
Setting value, range
and step
Description
Operation
Off
Peak value
Fundamental value
Operating mode selection of the function. Can be disabled,
operating based into measured current peak values or operating
based into calculated current fundamental frequency RMS
values. Def
ault setting is “Peak value”
Start
current
20
…3000 %, by step
of 1%
Pick-up setting of the function. Setting range is from 20% to
3000% of the configured nominal secondary current. Setting
step is 1 %. Default setting is 200 %
