Siemens siprotec 7SA6 User Manual

Functions
6-148 7SA6 Manual
C53000-G1176-C156-2
Figure 6-84 Logic diagram of the blocking scheme (one line end)
6.8.1.4 Transient Blocking
Transient blocking provides additional security against erroneous signals due to tran-
sients caused by clearance of an external fault or by fault direction reversal during
clearance of a fault on a parallel line.
The principle of transient blocking scheme is that following the incidence of an external
fault, the formation of a release signal is prevented for a certain (settable) time. In the
case of permissive schemes, this is achieved by blocking of the transmit and receive
circuit.
Figure 6-85 shows the principle of the transient blocking for a directional comparison
and directional unblocking scheme.
If a fault in the reverse direction is detected within the waiting time
TrBlk Wait Time
(address 3209A) following fault detection, the transmit circuit and the trip release are
inhibited. This blocking is maintained for the duration of the transient blocking time
TrBlk BlockTime (address 3210A) also after the reset of the blocking criterion.
In the case of the blocking scheme, the transient blocking prolongs the received block-
ing signal as shown in the logic diagram Figure 6-84.
3IoMin Teleprot
3203
Send Prolong.
&
T0
≥1
I
L1
, I
L2
, I
L3
d
dt
40 ms
(u,i)
(A)
U
L1
,U
L2
,U
L3
EF forward
&
&
EF Pickup
3208 Release Delay
0T
Line Config.
3202
Two terminals
Three terminals
EF Enable Trip
3209
TrBlk Wait Time
TT
3210
TrBlk BlockTime
&
≥1
&
&
&
EF Telep. off
1313
>EF TeleprotBLK
EF TeleTransBlk
1318
>EF Rec.Ch1
1319
>EF Rec.Ch2
EF Telep. OFF
1381
EF Tele SEND
1384
EF Tele BL STOP
1384
EF TeleTransBlk
1386
EF Tele BL Jump
1390

Siemens siprotec 7SA6 Specifications

General

Brand	Siemens
Model	siprotec 7SA6
Category	Relays
Language	English