Measuring The Trip Value For The Zero-Sequence Function - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.9.2.3
232
2
× = + ×
3 V V a V
2 A B
EQUATION1818-ANSI V1 EN
Where:
V V V
and
A B C
EQUATION1820-ANSI V1 EN
p ×
2
j
= × = -
a 1 e 0, 5
3
IECEQUATION00022 V2 EN
4. Compare the result with the set value of the negative-sequence operating voltage
(consider that the set value 3V2PU is in percentage of the base voltage VBase).
5. Repeat steps 1 and 2. Then slowly increase the measured current in one phase until
the BLKV signal disappears.
6. Record the measured current and calculate the corresponding negative-sequence
current according to the equation (observe that the currents in the equation are
phasors):
× = + × + ×
2
3 I I a I
2
A B
ANSIEQUATION00021 V1 EN
Where:
,
I I and I
A B C
ANSIEQUATION00020 V1 EN
p ×
2
j
= × = -
a 1 e 0, 5
3
IECEQUATION00022 V2 EN
7. Compare the result with the set value of the negative-sequence operating current.
Consider that the set value 3I2< is in percentage of the base current IBase.

Measuring the trip value for the zero-sequence function

Measure the trip value for the zero-sequence function, if included in the IED.
+ ×
a V
C
are the measured phase voltages
3
+
. j
2
a I
C
are the measured phase currents
3
+
. j
2
1MRK 504 165-UUS -
(Equation 104)
(Equation 105)
Transformer protection RET670 2.2 ANSI
Commissioning manual