terminal side of the generator) and ANGLE (the angle between the third-harmonic
voltage phasors U
3N
and U
3T
). The value of E3 should be close to the following value:
(
) (
)
2
2
3N
3T
3T
E3
U
U
cos(ANGLE)
U
sin(ANGLE)
=
-
×
+
×
EQUATION2076 V1 EN-US
(Equation 103)
Make sure that ANGLE has a value bigger than 125°
2.
Read the value of DU (differential voltage). The value of DU should be close to the
following value:
(
) (
)
2
2
3N
3T
3T
DU
U
U
cos(ANGLE)
U
sin(ANGLE)
=
+
×
+
×
EQUATION2078 V1 EN-US
(Equation 104)
3.
Read the value of BU (bias voltage:
Beta ·U
3N
). The ratio DU/BU should be well below 1 for
a non-faulted generator.
4.
After synchronization of the generator the ratio DU/BU is checked for different load
levels of the generator. These different monitoring of load levels should be the base for
the setting of
beta.
If the function is used with the option of neutral point measurement only the test is
performed by check of this voltage. The operate value should be above the measured
residual third-harmonic voltage in the neutral point at normal operation (non-faulted
generator).
12.6.6.3
Completing the test
SEMOD158990-34 v3
Continue to test another function or end the test by changing the
TestMode setting to Off.
Restore connections and settings to their original values, if they were changed for testing
purposes.
12.6.7
Loss of voltage check LOVPTUV
SEMOD175023-3 v5
Prepare the IED for verification of settings as outlined in section
and
in this chapter.
12.6.7.1
Measuring the operate limit of set values
SEMOD175023-7 v7
1.
Check that the input logical signals BLOCK, CBOPEN and VTSU are logical zero.
2.
Supply a three-phase rated voltage in all three phases and note on the local HMI that the
TRIP logical signal is equal to the logical 0.
3.
Switch off the voltage in all three phases.
After set
tTrip time a TRIP signal appears on the corresponding binary output or on the
local HMI.
Note that TRIP at this time is a pulse signal, duration should be according
to set
tPulse.
4.
Inject the measured voltages at rated values for at least set
tRestore time.
5.
Activate the CBOPEN binary input.
6.
Simultaneously disconnect all the three-phase voltages from the IED.
No TRIP signal should appear.
7.
Inject the measured voltages at rated values for at least set
tRestore time.
8.
Activate the VTSU binary input.
Section 12
1MRK 502 067-UEN B
Testing functionality by secondary injection
192
Commissioning manual
