ABB RER670 Applications Manual page 228

Section 12
Control
222
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:
• Off, the energizing function is disabled.
• DLLB, Dead Line Live Bus, the line voltage is below set value of
ULowLineEnerg and the bus voltage is above set value of UHighBusEnerg.
• DBLL, Dead Bus Live Line, the bus voltage is below set value of
ULowBusEnerg and the line voltage is above set value of UHighLineEnerg.
• Both, energizing can be done in both directions, DLLB or DBLL.
ManEnergDBDL
If the parameter is set to On, manual closing is also enabled when both line voltage
and bus voltage are below ULowLineEnerg and ULowBusEnerg respectively, and
ManEnerg is set to DLLB, DBLL or Both.
UHighBusEnerg and UHighLineEnerg
The voltage level settings must be chosen in relation to the bus or line network
voltage. The threshold voltages UHighBusEnerg and UHighLineEnerg have to be
set lower than the value at which the network is considered to be energized. A
typical value can be 80% of the base voltages.
ULowBusEnerg and ULowLineEnerg
1MRK 506 375-UEN A
Railway application RER670 2.2 IEC
Application manual