Table of Contents
Advertisement
Section 11
Testing functionality by secondary injection
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.
11.10.2.3
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):
3 U
IEC00000276 V1 EN-US
Where:
IEC00000275 V1 EN-US
4.
Compare the result with the set value of the zero-sequence operating voltage (consider that the
set value 3U0> is in percentage of the base voltage.)
224
a
2
a
⋅
U
=
U
+
⋅
U
+ ⋅
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
×
=
U
+
U
+
U
0
L1
L2
L3
U
, U
and U
L1
L2
L3
are the measured phase voltages
© 2017 - 2022 Hitachi Energy. All rights reserved
U
L3
are the measured phase voltages
3
2
3
are the measured phase currents
3
2
1MRK 504 165-UEN Rev. K
(Equation 117)
(Equation 118)
M1405-72 v11
(Equation 119)
Transformer protection RET670
Commissioning manual
Advertisement
Table of Contents
