ABB Relion 670 series - Measuring the Operate Value for the Negative Sequence Function; Measuring the Operate Value for the Zero-Sequence Function

• Signal 3PH after about 25ms
• Signal BLKU after about 50ms
• Signal BLKZ after about 200ms
15.10.2.2 Measuring the operate value for the negative sequence function
Measure the operate value for the negative sequence 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. Slowly decrease the measured voltage in one phase until the BLKU signal
appears.
3. Record the measured voltage and calculate the corresponding negative-
sequence voltage according to the equation.
Observe that the voltages in the equation are phasors.
3 U
2
× U
L1
a
2
U
L2
a+× U
L3
×+=
EQUATION707 V1 EN (Equation 18)
Where:
U
L1
U
L2
and U
L3
EQUATION708 V1 EN
= the measured phase voltages
a 1 e
j
2 p×
3
-----------
× 0 5 j
3
2
-------
+,–= =
EQUATION709 V1 EN
4. Compare the result with the set value (consider that the set value 3U2> is in
percentage of the base voltage UBase) of the negative-sequence operating
voltage.
15.10.2.3 Measuring the operate value for the zero-sequence function
Measure the operate value for the zero-sequence 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. 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.
1MRK 502 029-UEN A Section 15
Verifying settings by secondary injection
211
Installation and commissioning manual