Table of Contents
Advertisement
Section 10
Testing functionality by secondary injection
10.6.1.3
86
×
=
+
×
2
3
I
I
a
I
2
L
1
L
2
IECEQUATION00021 V1 EN
Where:
,
I
I and I
L
1
L
2
L
3
IECEQUATION00020 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 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
=
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 of the zero-sequence operating voltage
(consider that the set value 3U0> is in percentage of the base voltage.)
5.
Repeat steps
1
and 2. Then slowly increase the measured current in one phase
until the BLKU signal disappears.
6.
Record the measured current and calculate the corresponding zero-sequence
current according to the equation (observe that the currents in the equation are
phasors):
+ ×
a I
L
3
are the measured phase currents
3
+
.
j
2
+
U
L3
are the measured phase voltages
1MRK 504 160-UEN -
(Equation 2)
(Equation 3)
Transformer protection RET650 2.1 IEC
Commissioning manual
Advertisement
Table of Contents
