Measuring The Operate Value For The Zero-Sequence Function; Checking The Operation Of The Du/Dt And Di/Dt Based Function - ABB RET670 Installation And Commissioning Manual

1MRK 504 088-UEN C
13.10.2.3
13.10.2.4
Installation and commissioning manual

Measuring the operate value for the zero-sequence function

Measure the operate value for the zero-sequence function, if included in the IED.
Procedure
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. Slowly decrease the measured voltage in one phase until the BLKU signal
appears.
3. Record the measured voltage and calculate the corresponding zero-sequence
voltage according to the equation.
Observe that the voltages in the equation are phasors.
×
3 U = U + U
0 L1 L2
IEC00000276 V1 EN
Where:
U , U and U
L1 L2 L3
IEC00000275 V1 EN
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.

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.
Procedure
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.
5. Change the voltages and currents in all three phases simultaneously.
Verifying settings by secondary injection
+ U
L3
Section 13
(Equation 16)
= the measured phase voltages.
173