ABB REB670 Series, Applications Manual

Page: 268 / 476

The setting
tMinSynch is set to limit the minimum time at which the synchronizing closing
attempt is given. The synchronizing function will not give a closing command within this time,
from when the synchronizing is started, even if a synchronizing condition is fulfilled. A typical
setting is 200 ms.
Synchrocheck settings
OperationSC
The
OperationSC setting Off disables the synchrocheck function and sets the outputs
AUTOSYOK, MANSYOK, TSTAUTSY and TSTMANSY to low. With the setting
On, the function is
in the service mode and the output signal depends on the input conditions.
UHighBusSC and UHighLineSC
The voltage level settings must be chosen in relation to the bus or line network voltage. The
threshold voltages
UHighBusSC and UHighLineSC have to be set lower than the value at which
the breaker is expected to close with the synchronism check. A typical value can be 80% of the
base voltages.
UDiffSC
The setting for voltage difference between line and bus in p.u. This setting in p.u. is defined as
(U-Bus/
GblBaseSelBus) - (U-Line/GblBaseSelLine). A normal setting is 0,10-0,15 p.u.
FreqDiffM and FreqDiffA
The frequency difference level settings, FreqDiffM and FreqDiffA, shall be chosen depending
on the condition in the network. At steady conditions a low frequency difference setting is
needed, where the
FreqDiffM setting is used. For autoreclosing a bigger frequency difference
setting is preferable, where the
FreqDiffA setting is used. A typical value for FreqDiffM can
be10 mHz, and a typical value for
FreqDiffA can be 100-200 mHz.
PhaseDiffM and PhaseDiffA
The phase angle difference level settings,
PhaseDiffM and PhaseDiffA, shall also be chosen
depending on conditions in the network. The phase angle setting must be chosen to allow
closing under maximum load condition. A typical maximum value in heavy-loaded networks can
be 45 degrees, whereas in most networks the maximum occurring angle is below 25 degrees.
The PhaseDiffM setting is a limitation to PhaseDiffA setting. Fluctuations occurring at high
speed autoreclosing limit PhaseDiffA setting.
tSCM and tSCA
The purpose of the timer delay settings,
tSCM and tSCA, is to ensure that the synchrocheck
conditions remains constant and that the situation is not due to a temporary interference.
Should the conditions not persist for the specified time, the delay timer is reset and the
procedure is restarted when the conditions are fulfilled again. Circuit breaker closing is thus
not permitted until the synchrocheck situation has remained constant throughout the set
delay setting time. Manual closing is normally under more stable conditions and a longer
operation time delay setting is needed, where the
tSCM setting is used. During auto-reclosing,
a shorter operation time delay setting is preferable, where the tSCA setting is used. A typical
value for tSCM can be 1 second and a typical value for tSCA can be 0.1 seconds.
Energizingcheck settings
AutoEnerg and ManEnerg
Two different settings can be used for automatic and manual closing of the circuit breaker.
The settings for each of them are:
Section 12 1MRK 505 370-UEN D
Control
262 Busbar protection REB670
Application manual