4.
To start reading the measurements, click the Start reading values from IED button in the
ICT toolbar.
ICT starts to read the selected viewed quantity from IED and plots values on the X/Y
graph.
Measured absolute
impedance ± standard
deviation
Measured absolute
impedance
Floating average of the
measured absolute
impedance
Reference Impedance
Selection dropdown
menu
IEC11000046-1-en.vsd
GUID-FAE32C52-80F0-4AEF-AA0D-6BA39F896712 V1 EN-US
Figure 14: Commissioning tab
Normally continuous readings are performed and the read absolute impedance is viewed
in the plot.
By observing the standard deviation of the measured impedance, the commissioning
engineer can decide if the impedance of the generator is stable/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 a second 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.
6.6
Verifying calibration
GUID-3805BA77-6369-4798-8E1B-1201A0B9C68A v3
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.
Section 6
1MRK 502 067-UEN B
Calibrating injection based sensitive rotor earth fault protection
58
Commissioning manual
