1. Check that the settings in the IED are appropriate, especially the START value
and the definite time delay. Set StartFreqGrad, to a rather small negative value.
2. Supply the IED with three-phase voltages at their rated values.
3. Slowly decrease the frequency of the applied voltage, with an increasing rate-of-
change that finally exceeds the setting of StartFreqGrad, and check that the
START signal appears.
4. Note the operate value and compare it with the set value.
5. Increase the frequency to rated operating conditions, and zero rate-of-change.
6. Check that the START signal resets.
7. Instantaneously decrease the frequency of the applied voltage to a value about
20% lower than the nominal value.
8. Measure the time delay for the TRIP signal, and compare it with the set value.
Extended testing
1. The test above can be repeated to check a positive setting of StartFreqGrad.
2. The tests above can be repeated to check the time to reset.
3. The tests above can be repeated to test the RESTORE signal, when the frequency
recovers from a low value.
10.7.3.2 Completing the test
Continue to test another function or end the test by changing the TestMode setting to
Off. Restore connections and settings to their original values, if they were changed for
testing purposes.
10.8 Multipurpose protection
10.8.1 General current and voltage protection CVGAPC
Prepare the IED for verification of settings as outlined in section "Requirements" and
section
"Preparing for test" in this chapter.
One of the new facilities within the general current and voltage protection function
CVGAPC is that the value, which is processed and used for evaluation in the function,
can be chosen in many different ways by the setting parameters CurrentInput and
VoltageInput.
These setting parameters decide what kind of preprocessing the connected three-
phase CT and VT inputs shall be subjected to. That is, for example, single-phase
quantities, phase-to-phase quantities, positive sequence quantities, negative sequence
quantities, maximum quantity from the three-phase group, minimum quantity from
the three-phase group, difference between maximum and minimum quantities
(unbalance) can be derived and then used in the function.
1MRK 506 355-UEN A Section 10
Testing functionality by secondary injection
Line distance protection REL670 2.1 IEC 185
Commissioning manual
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