Siemens SIPROTEC 7SS52, Operation Manual

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Siemens AG
⋅
May 1998
three-phase
TRIPcommand
P
t
1
T-CBF
(zone-selective)
L - k x ȧ ā ȧ
> 0
transfer trip
command
(feeder-selective)
P 1/2-channel
BI suĆ
pervision
1
unbalancing
Lx
TRIP-R.OP.
P
P
T-TRIP-REP
P >CBF Ayy
P >CBF Ayy
( Lx &
E
)
three-phase
TRIPrepetition
phase-selectiv
TRIPrepetition
(feeder-selective)
(feeder-selective)
t
1
(figure 4.32,
chapter 4.7.8.5)
&
&
P >CBF Ayy
trip criteĆ
rion fulfilĆ
led?
( Lx & Ly) v
( Lx &
E
)
( Lx & Ly) v
( Lx &
E
)
Figure 4.17 Flow-chart for TRIP repetition and unbalancing
In the operation mode "TRIP-rep/unb" (
) the CBF is initiated feeder-selective by the TRIP
command. The release signal is usually fault detection
by the feeder protection.
Simultaneously the time delay for TRIPrepetition T-
TRIP-REP ( ) and the time delay for unbaĆ
lancing T-CBF ( ) are started.
The TRIPrepetition time must be shorter than the
CBF time delay.
TRIPrepetition is issued only when the feeder-selecĆ
tive CBF initiation together with the common CBF
release persist after the time delay T-TRIP-REP
( ) has elapsed.
TRIPrepetition can alternatively be set to single-
phase or three-phase by the common parameter
"TRIP-R.OP" ( ) (equivalent to chapter
4.6.1.2).
If the TRIPrepetition does not effect reset of the proĆ
tection, then unbalancing is initiated after the time
delay T-CBF ( ) has elapsed (equivalent to
chapter 4.6.1.3).
The flow-chart is shown in figure 4.17.
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