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Section 7
Testing functionality
be tested separately by means of fundamental frequency voltage injection from a test
equipment.
7.6.5.2
Verifying settings
1.
With the generator rotating at rated speed but not connected: check the value of the
following analogue signals: E3 (the magnitude of the 3
stator), U
the generator), U
terminal side of the generator) and ANGLE (the angle between the third-harmonic
voltage phasors U
E3
EQUATION2076 V1 EN-US
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:
DU
EQUATION2078 V1 EN-US
3.
Read the value of BU (bias voltage:
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
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).
7.6.5.3
Completing the test
Continue to test another function or end the testing by setting the parameter
under Main menu/Tests/IED test mode/1:TESTMODE. If another function is tested, then set
the parameter
STEFPHIZ(59THD)/1:STEFPHIZ for the function, or for each individual function in a chain, to be
tested next. Remember to set the parameter
has been tested.
7.6.6
Rotor earth fault protection 64R
Generator rotor winding and its associated dc supply electric circuit is typically fully insulated
from the earth (that is, ground). Therefore single connection of this circuit to earth will not
cause flow of any substantial current. However if second earth fault appears in this circuit
circumstances can be quit serious. Depending on the location of these two faults such
operating condition may cause:
•
Partial or total generator loss of field
•
Large dc current flow through rotor magnetic circuit
•
Rotor vibration
•
Rotor displacement sufficient to cause stator mechanical damage
70
(the magnitude of the third-harmonic voltage measured at the neutral side of
3N
(the magnitude of the third-harmonic voltage measured at the
3T
and U
3N
3T
(
=
-
×
U
U
cos(ANGLE)
3 N
3T
(
=
+
×
U
U
cos(ANGLE)
3 N
3T
beta .
Blocked to No under Main menu/Tests/Function test modes/Voltage/
© Copyright 2011 ABB. All rights reserved
). The value of E3 should be close to the following value:
) (
2
+
×
U
sin(ANGLE)
3T
) (
2
+
×
U
sin(ANGLE)
3T
Beta ·U
). The ratio DU/BU should be well below 1 for
3N
Blocked to Yes , for each individual function that
1MRK 502 035-UEN A
rd
harmonic induced voltage in the
)
2
)
2
TestMode to Off
Generator protection REG650
Commissioning manual
SEMOD158990-144 v3
(Equation 26)
(Equation 27)
SEMOD158990-34 v3
SEMOD151286-4 v3
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