Arcteq Generator Commander, Instruction Manual

Page: 238 / 561

• digital inputs and logic signals
• measured and pre-processed impedance magnitudes.
The function's outputs are START, TRIP and BLOCKED signals which can be used for direct I/O
controlling and user logic programming. The function generates general time-stamped ON/OFF events
to the common event buffer from each of the three (3) output signals. In the instant operating mode the
function outputs START and TRIP events simultaneously with an equivalent time stamp. The time stamp
resolution is 1 ms. The function also provides a resettable cumulative counter for the START, TRIP and
BLOCKED events.
Figure. 5.4.23 - 122. Simplified function block diagram of the Z< function.
Measured input
Sufficient current and voltage measurements are required for the impedance measurement to work
properly. The user can select the monitored magnitude to be equal to either phase-to-earth impedance
loops, phase-to-phase impedance loops, or the positive sequence impedance. A -20ms averaged
value of the selected magnitude is used for pre-fault data registering.
Please note that impendance calculations are enable in
Measurement
→
Impedance Calculations
→
Impedance calc. settings to ensure that the function calculates the listed values.
Table. 5.4.23 - 203. Measurement inputs of the Z< function.
Signal Description Time base
Z1 Impedance of phase-to-earth (P1-E) 5ms
Z2 Impedance of phase-to-earth (P2-E) 5ms
Z3 Impedance of phase-to-earth (P3-E) 5ms
Z12 Impedance of phase-to-phase (P1-P2) 5ms
Z23 Impedance of phase-to-phase (P2-P3) 5ms
Z31 Impedance of phase-to-phase (P3-P1) 5ms
Pos.Seq.Imp Positive sequence impedance 5ms
General settings
The following general settings define the general behavior of the function. These settings are static i.e.
it is not possible to change them by editing the setting group.
Genera Generattor Commander or Commander
Instruction manual
Version: 2.07
236 © Arcteq Relays Ltd
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