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1MRK 505 372-UEN Rev. K
10.8.1.2
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
EQUATION707 V2 EN-US
Where:
IEC00000275 V1 EN-US
a
IECEQUATION00022 V2 EN-US
4.
Compare the result with the set value of the negative-sequence operating voltage (consider
that the set value 3U2> is in percentage of the base voltage UBase).
5.
Repeat steps
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):
3
IECEQUATION00021 V1 EN-US
Where:
I
IECEQUATION00020 V1 EN-US
a
IECEQUATION00022 V2 EN-US
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.
10.8.1.3
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):
Busbar protection REB670
Commissioning manual
⋅
U
=
U
+
a
2
⋅
U
+ ⋅
a
2
L
1
L2
U
, U
and U
L1
L2
L3
p ×
2
j
= ×
= -
+
1
e
0, 5
.
j
3
1
and 2. Then slowly increase the measured current in one phase until the BLKU
×
=
+
2
×
+ ×
I
I
a
I
a I
2
L
1
L
2
L
,
I and I
L
1
L
2
L
3
p ×
2
j
= ×
= -
+
1
e
0, 5
.
j
3
© 2017 - 2022 Hitachi Energy. All rights reserved
U
L3
are the measured phase voltages
3
2
3
are the measured phase currents
3
2
Section 10
Testing functionality by secondary injection
(Equation 22)
(Equation 23)
M1405-46 v12
M1405-72 v11
113
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