Siemens siprotec 7SD5 User Manual

2.7 Teleprotection for Distance Protection (optional)
179
7SD5 Manual
C53000-G1176-C169-1
2.7.4 Permissive Underreach Transfer Trip with Zone Acceleration Z1B (PUTT)
Principle Figure 2-69 shows the operation scheme for the permissive underreach transfer trip
with zone acceleration. In the case of a fault inside zone Z1, the transfer trip signal is
sent to the opposite line end. The signal received there causes tripping if the fault is
detected in the pre-set direction inside the zone Z1B. The transmit signal can be pro-
longed by T
S
(settable in address 2103 Send Prolong.), to compensate 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, the overreaching
zone, however, is set to reach beyond the opposite substation (approximately 120%
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. Z1B must securely reach
beyond the longer line section, even when additional infeed is possible via the tee
point.
In address 121 Teleprot. Dist. the option PUTT (Z1B) can be configured.
Address 2101 FCT Telep. Dis. allows to switch the teleprotection scheme (ON).
Figure 2-69 Operation scheme of the permissive underreach transfer trip via Z1B
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Siemens siprotec 7SD5 Specifications

General

Brand	Siemens
Model	siprotec 7SD5
Category	Relays
Language	English