ABB Relion 670 series, Installation And Commissioning Manual

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settled, and also if the average impedance is based on enough values so that
statistically the signal noise is “filtered out”. This results in a fairly accurate
impedance measurement which can be used as an alternative reference.
5. Click the Select button when the standard deviation has converged so that its
magnitude is within the noise level of the measured absolute impedance.
In the second commissioning sub tab, Step2 : Save Reference Impedance, the
measured real and imaginary reference 2 impedance is presented.
6. Select the Submit to Parameter setting button.
This forwards the newly acquired reference to Parameter setting.
7. Write the newly acquired real and imaginary parts of Reference 2 to IED.
10.6 Verifying calibration
After the calibration is performed, it is appropriate to verify that known faults are
measured as expected and that the function is indicating trips and alarms when it
should, in other words that the calibration was successful. For this purpose the
monitoring feature can be used.
1. In the ICT toolbar, select the fourth tab, Monitoring .
Logger feature
Currently measured
impedance and its
average
Selectable quantity for
plotting
Selectable graph
update period
Currently used reference
IEC11000050-1-en.vsd
GUID-DCE099B6-4DBA-4A52-9566-0E20B8AF7712 V1 EN
Figure 71: Monitoring tab
2. Set the graph update period to one second by typing 1 into the Graph update
period field.
3. To start continuously plotting values on the graph with one second interval,
select
Start readings from IED .
Section 10
1MRK 502 029-UEN A
Calibrating injection based sensitive rotor earth fault protection
114
Installation and commissioning manual