Siemens siprotec 7SD5, Руководство пользователя

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2.7 Teleprotection for Distance Protection (optional)
177
7SD5 Manual
C53000-G1176-C169-1
2.7.3 PUTT (Pickup)
The following scheme is suited for conventional transmission media.
Principle The PUTT scheme functionality is shown in Figure 2-67. In the case of a fault inside
zone Z1, the transfer trip signal is sent to the opposite line end. The signal received
there initiates the trip, provided that the protection function has picked up. The transmit
signal can be prolonged by T
S
(settable in address
2103 Send Prolong.
), to com-
pensate for possible differences in the pickup time at the two line ends. The distance
protection is set such that the first zone reaches up to approximately 85% of the line
length. On three terminal lines Z1 is also set to approximately 85 % of the shorter line
section, but at least beyond the tee-off point.
The overreach zone Z1B is without consequence for the teleprotection scheme in this
operating mode. It may, however, be controlled by the automatic reclosing function
(see also section 2.10.1).
Figure 2-67 Operation scheme of the permissive underreach transfer trip with pickup
Sequence The permissive transfer trip should only send for faults in the „Forward“ direction. Ac-
cordingly, the first zone Z1 of the distance protection must definitely be set to
Forward
in address
1601 Op. mode Z1
, refer also to Section 2.5.1 under the margin
heading „Independent Zones Z1 up to Z5“.
On two terminal lines, the signal transmission may be phase segregated. Send and
receive circuits in this case are built up for each phase. On three terminal lines, the
transmit signal is sent to both opposite line ends. The receive signals are then com-
bined with an OR logic function. With the setting parameter
Type of Line
(address
2102
) the device is informed as to whether it has one or two opposite line ends.
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