Direct Underreach Transfer Trip - Siemens siprotec 7SA522 User Manual

Functions
6.4.1.2

Direct Underreach Transfer Trip

Principle
6-80
Dis Telep. off
4003 >Dis.Telep. Blk
! "
Dis. forward
&
Dis Z1 L1
&
Dis Z1 L2
&
Dis Z1 L3
&
Dis Z1
! ! GvrÃ8‚svtÃ
„1"
4006 >DisTel Rec.Ch1
4010 >DisTel Rec.Ch2
4007 >Dis.T.Rec.Ch1 L1
4008 >Dis.T.Rec.Ch1 L2
4009 >Dis.T.Rec.Ch1 L3
Figure 6-45 Logic diagram of the permissive underreach transfer trip (PUTT) scheme using
Z1B (one line end)
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
(settable under address  7ULS 7LPH '(/$<) (Figure 6-46). The transmit sig-
T
v
nal can be prolonged by T
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.
≥1
TrqÃQ…‚y‚tÃ
0 T
0 T
0 T
0 T
Two terminals
Three terminals
≥1
Two terminals
Three terminals
(settable under address  6HQG 3URORQJ), to com-
S
4052
Dis.Telep.OFF
&
4057
Dis.T.SEND L1
&
4058 Dis.T.SEND L2
&
Dis.T.SEND L3
4059
&
4056
Weak infeed
&
≥1
&
Dis Enable Z1B/T1B L1
≥1
&
Dis Enable Z1B/T1B L2
≥1
&
Dis Enable Z1B/T1B L3
C53000-G1176-C119-2
Dis.T.SEND
tripping
7SA522 Manual