Instruction manual
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AQ G3x7 Generator protection IED
12 (211
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Figure 3-2
Example connection with phase currents connected into summing “Holmgren”
connection into the I0 residual input.
Phase current CT:
CT primary 100A
CT secondary 5A
Ring core CT in Input I0:
I0CT primary 100A
I0CT secondary 5A
Phase currents are
connected to summing “Holmgren” connection into the I0
residual input.
The sampled values are available for further processing and for disturbance recording.
The performed basic calculation results the Fourier basic harmonic magnitude and angle
and the true RMS value. These results are processed by subsequent protection function
blocks and they are available for on-line displaying as well.
The function block also provides parameters for setting the primary rated currents of the
main current transformer (Rated Primary I1-3 and Rated Primary I4). This function block
does not need that parameter settings. These values are passed on to function blocks such
as displaying primary measured values, primary power calculation, etc.
Table 3-3 Enumerated parameters of the current input function