ABB RET670 Commissioning Manual page 254

Section 11
Testing functionality by secondary injection
248
• Short circuit impedance, available on the local HMI under Main menu/
Settings/General settings/Control/TransformerVoltageControl(ATCC,
90)/TR1ATCC:x/TR8ATCC:x/Xr2.
• Confirm that the setting for TCMYLTC (84) or TCLYLTC (84) is in accordance with
transformer data:
• Tap change timeout duration - effectively the maximum transformer tap change
time, tTCTimeout, available on the local HMI under Main menu/Settings/
Setting Group N/Control/TransformerTapControl(YLTC,84)/
TCMYLTC:x/TCLYLTC:x/tTCTimeout.
• Load tap changer pulse duration - required length of pulse from IED to load tap
changer, tPulseDur, available on the local HMI under Main menu/Settings/
Setting Group N/Control/TransformerTapControl(YLTC,84)/
TCMYLTC:x/TCLYLTC:x/tPulseDur.
• Transformer tap range, LowVoltTap and HighVoltTap, available on the local
HMI under Main menu/Settings/General Settings/Control/
TransformerTapControl(YLTC,84)/TCMYLTC:x/TCLYLTC:x/
HighVoltTap and .
• Load tap changer code type - method for digital feedback of tap position,
CodeType, available on the local HMI under Main menu/Settings/ General
settings/Control/TransformerTapControl(YLTC,84)/TCMYLTC:x/
TCLYLTC:x/CodeType.
During the installation and commissioning, the behavior of the voltage
control functions for different tests may be governed by a parameter
group, available on the local HMI under Main menu/Settings/General
settings/Control/TransformerVoltageControl(ATCC,90)/
TR1ATCC:x/TR8ATCC:x. These parameter settings can cause a Total
Block, Automatic Block or Alarm for a variety of system conditions
including over and under voltage, over current and tap changer failure. It
is important to review these settings and confirm the intended response of
the voltage control function for different secondary injection tests.
Terminology
The busbar voltage V is a shorter notation for the measured voltages Va, Vb, Vc or Vij,
B
where Vij is the phase-phase voltage, Vij = Vi -Vj, or Vi, where Vi is one single-phase-to-
ground voltage.
I is a shorter notation for the measured load current; it is to be used instead of the three-
L
phase quantities Ia, Ib, Ic or the two-phase quantities Ii and Ij, or single-phase current Ii.
1MRK 504 165-UUS -
Transformer protection RET670 2.2 ANSI
Commissioning manual