ABB Relion 670 series, Installation And Commissioning Manual

Page: 218 / 260

3 U
0
×
U
L1
U
L2
U
L3
+ + =
IEC00000276 V1 EN
(Equation 21)
Where:
U
L1
, U
L2
and U
L3
IEC00000275 V1 EN
= the measured phase voltages.
4. Compare the result with the set value (consider that the set value 3U0> is in
percentage of the base voltage of the zero-sequence operating voltage.
15.10.2.4 Checking the operation of the du/dt and di/dt based function
Check the operation of the du/dt and di/dt based function, if included in the IED.
1. Simulate normal operating conditions with the three-phase currents in phase
with their corresponding phase voltages and with all of them equal to their
rated values.
2. Connect the nominal dc voltage to the CBCLOSED binary input.
3. Change the voltages and currents in all three phases simultaneously.
The voltage change should be greater then set
DU> and the current change
should be less than the set DI< .
• The BLKU and BLKZ signals appear without any time delay. The
BLKZ signal will be activated, only if the internal deadline detection is
not activated at the same time.
• 3PH should appear after 5 seconds, if the remaining voltage levels are
lower than the set
UDLD< of the DLD function.
4. Apply normal conditions as in step 3 .
The BLKU, BLKZ and 3PH signals should reset, if activated, see step 1 and 3 .
5. Change the voltages and currents in all three phases simultaneously.
The voltage change should be greater than set
DU> and the current change
should be greater than the set DI< .
The BLKU, BLKZ and 3PH signals should not appear.
6. Disconnect the dc voltage to the CBCLOSED binary input.
7. Apply normal conditions as in step 1 .
8. Repeat step 3 .
9. Connect the nominal voltages in all three phases and feed a current below the
operate level in all three phases.
10. Keep the current constant. Disconnect the voltage in all three phases
simultaneously.
The BLKU, BLKZ and 3PH signals should not appear.
15.10.2.5 Completing the test
Continue to test another function or end the test by changing the Test mode setting
to Off . Restore connections and settings to their original values, if they were
changed for testing purposes.
Section 15
1MRK 502 029-UEN A
Verifying settings by secondary injection
212
Installation and commissioning manual