Siemens siprotec 7SA522, User Manual

Page: 228 / 628

Functions
6-80
7SA522 Manual
C53000-G1176-C119-2
Figure 6-45 Logic diagram of the permissive underreach transfer trip (PUTT) scheme using
Z1B (one line end)
6.4.1.2 Direct Underreach Transfer Trip
Principle As is the case with permissive transfer trip via zone acceleration, a fault in the first
zone Z1 is transmitted to the opposite line end by means of a transfer trip signal. The
signal received there causes a trip without further queries after a short security margin
T
v
(settable under address
7ULS7LPH'(/$<
) (Figure 6-46). The transmit sig-
nal can be prolonged by T
S
(settable under address
6HQG3URORQJ
), to com-
pensate for possible differences in the pick-up time at the two line ends. The distance
protection is set such that the first zone reaches up to approximately 80 % of the line
length. On three terminal lines Z1 is also set to approximately 80 % of the shorter line
section, but at least beyond the tee off point. The overreaching zone Z1B is not re-
quired here. It may however be activated by internal automatic reclosure or external
criteria via the binary input “
!(QDEOH$5]RQHV
” (refer also to Figure 6-39 bottom).
The advantage compared to the permissive underreach transfer trip with zone accel-
eration lies in the fact that both line ends are tripped without the necessity for any fur-
ther measures, even if one line end has no infeed. There is however no further super-
vision of the trip signal at the receiving end.
4007 >Dis.T.Rec.Ch1 L1
4006 >DisTel Rec.Ch1
Dis Telep. off
≥
1
Dis Z1 L1
&
Dis Z1 L2
&
Dis Z1 L3
&
Dis Z1
&
Dis. forward
T 0
T 0
T 0
T 0
&
&
&
&
&
&
&
≥
1
≥
1
≥
1
Dis Enable Z1B/T1B L2
Dis Enable Z1B/T1B L3
Weak infeed
Dis Enable Z1B/T1B L1
Three terminals
Two terminals
Three terminals
Two terminals
„1“
/LQH&RQILJ
≥
1
&
Dis.Telep.OFF
Dis.T.SEND L1
Dis.T.SEND L2
Dis.T.SEND L3
Dis.T.SEND
tripping
6HQG3URORQJ
4003 >Dis.Telep. Blk
4057
4058
4059
4056
4010 >DisTel Rec.Ch2
4008 >Dis.T.Rec.Ch1 L2
4009 >Dis.T.Rec.Ch1 L3
4052