Secondary Test; Check The Activation Of The Voltage Control Operation - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.10.3.1
11.10.3.2
238
Terminology
The busbar voltage U is a shorter notation for the measured voltages UL1, UL2,
B
UL3 or Uij, where Uij is the phase-phase voltage, Uij = Ui -Uj, or Ui, where Ui is
one single-phase-to-earth voltage.
I is a shorter notation for the measured load current; it is to be used instead of the
L
three-phase quantities IL1, IL2, IL3 or the two-phase quantities Ii and Ij, or single-
phase current Ii.
Also note that for simplicity, the Parameter Setting menu structures
included in the following procedure are referred to universally as
VCP1, for example, Main menu/Settings/Setting Group N/
Control/TransformerVoltageControl(ATCC,90)/TR1ATCC:x/
TR8ATCC:x/Time/t1 and t2l.
For cases where single-mode voltage control is implemented, the Parameter Setting
menu structure includes TR1ATCC:1 instead of the parallel designator TR8ATCC:
1.

Secondary test

The voltage control function performs basic voltage regulation by comparing a
calculated load voltage (U
(with upper and lower limits U2 and U1 respectively). The calculated load voltage
U represents the secondary transformer bus voltage U
L
compensation (LDC) where enabled in settings.
Note that when LDC is disabled, U
When the load voltage U
will be taken.
If U < U1 or U > U2, a command timer will start, which is constant time or
L L
inverse time defined by setting t1 and t1Use. The command timer will operate
while the measured voltage stays outside the inner deadband (defined by setting
UDeadbandInner).
If U remains outside of the voltage range defined by UDeadband and the
L
command timer expires, the voltage control will execute a raise or lower command
to the transformer tap changer. This command sequence will be repeated until U
brought back within the inner deadband range.

Check the activation of the voltage control operation

) against a voltage range defined by setting UDeadband
L
stays within the interval between U1 and U2, no action
L
1MRK 504 165-UEN A
adjusted for Load drop
B
equals U .
B L
Transformer protection RET670 2.2 IEC
Commissioning manual
SEMOD175185-145 v5
is
L
SEMOD175185-537 v8