Instruction manual
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AQ G3x7 Generator protection IED
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Status signals.
The function can be enabled or disabled (BLK input signal). The status signal of the VTS
(voltage transformer supervision) function can also disable the directional operation.
The outputs are
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The binary output status signals.
Software modules of the function block are as follows:
P-Q Calculation
Based on the RMS values of the fundamental Fourier component of the three phase
currents and of the three phase voltages, this module calculates the three-phase active and
reactive power values.
The input signals are the RMS values of the fundamental Fourier components of the three
phase currents and three phase voltages.
The internal output signals are the calculated three-phase active and reactive power
values.
Directional decision
This module decides if, on the power plane, the calculated complex power is closer to the
origin than the corresponding point of the characteristic line, i.e. if the point S is on the
“Operate” side of
the P-Q plane.
The internal input signals are the calculated active and reactive power values.
The internal output signal is the start signal of the function.
Decision logic
This part of the function block combines status signals to make a decision to start.
Additionally to the directional decision, the function may not be blocked by the general
“Block” signal, and may not be blocked by the signal “Block for VTS” of the voltage
transformer supervision function.
