ABB ret650, Руководство по вводу в эксплуатацию, Страница: 76 / 110

U
L
represents the secondary transformer bus voltage UB adjusted for Load drop
compensation (LDC) where enabled in settings.
Note that when LDC is disabled, UB equals U
L
.
When the load voltage U
L
stays within the interval between U1 and U2, no action
will be taken.
If U
L
< U1 or U
L
> U2, a command timer will start, which is constant time or
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
L
remains outside of the voltage range defined by UDeadband and the
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
L
is brought back within the inner deadband range.
6.7.1.2 Check the activation of the voltage control operation
1. Confirm Transformer Tap Control = On and Transformer Voltage Control =
On
• Direct tap change control
Main menu/Settings/IED Settings/Control/TCMYLTC (84)/
1:TCMYLTC/Operation
• Automatic transformer voltage control
Main menu/Settings/IED Settings/Control
• Enable Tap Command
Commands to tap changer are enabled per default.
While the test set is connected to the IED but no voltage is applied, the
voltage control functions will detect an undervoltage condition that may
result in an alarm or blocking of the voltage-control operation. These
conditions will be shown on the local HMI.
2. Apply the corresponding voltage
Confirm the analog measuring mode prior to undertaking secondary injection
(positive sequence, phase-phase, or phase-earth). This measuring mode is
defined in the local HMI under
Main menu/Settings/IED Settings/Control/
TR8ATCC (90)/1:TR8ATCC/General/MeasMode
The application of nominal voltage USet according to set MeasMode to the
IEDs should cause the alarm or blocking condition for undervoltage to reset.
Section 6
1MRK 504 126-UEN -
Testing functionality
68
Commissioning Manual