Applications For Analog And/Or Digital Transmission; Applications For Digital Transmission - Siemens SWT-3000 Equipment Manual

Functional Description

Applications for analog and/or digital transmission

The SWT 3000 system is used for fast, reliable transmission of several commands for protection
and/or special switching functions in supply networks.
Protection functions:
Switching functions:
Operating mode 4
3 independent
commands
4 independent
commands
2plus2 mode
Information on assignment of the frequencies for the individual operating modes can be found in
the section "Protection operating modes".

Applications for digital transmission

Two digital line interfaces (LID-1 and LID-2) are available through expansion of the PU3 module
with the interface module to digital transmission paths DLE (digital line equipment).
The hardware interfaces X.21 (up to 64kbit/s), G703.1 (64kbit/s) and G703.6 (2Mbit/s HDB3-
coded balanced or coaxial) can be selected on every LID, although only one can be used per LID.
The LID-1 can be operated alone or jointly with the LID-2 (multipath transmission). Operation with
different line interfaces is possible for LID-1 und LID-2 with multipath transmission. LID-1 is always
used if only one interface is needed.
When using exclusively digital interfaces up to 8 signal inputs can be transmitted transparently to
the distant station with Operating Mode 5D and can be jumpered to signal outputs there. Two in-
terface modules of type IFC-P and/or IFC-D are necessary for this application.
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Commands can be transmitted for the protection of two three-phase sys-
tems (double system protection) or one three-phase system with single-
phase protection (single-phase protection). High-voltage power switches
can be operated in conjunction with selective protection relays. This is
designated as a "permissive protection system". Direct switch operation
is also possible. This is known as "intertripping", "transfer tripping" or "di-
rect tripping".
It is possible to transmit four individual commands. Several commands
can be activated simultaneously. They are arranged according to priority
(input 1, 2, 3, and 4) and output one after the other.
Only one of the signal inputs 1 to 3 may be active in this operating mode.
Input 4 has priority and is treated independently of the states of input 1 to
3. This means that if input 4 is active the state of the other inputs in insig-
nificant. If more than one of signal inputs 1 to 3 is active and input 4 is in-
active that is an input error. The idle tone (guard) continues to be trans-
mitted.
Three signal inputs are available in this operating mode.
On the transmit side every possible combination of signal input is as-
signed to a protection frequency. On the receive side each protection fre-
quency can be assigned to one or more signal outputs (1 to 4).
Four signal inputs are available in this operating mode.
On the transmit side every possible combination of signal input is as-
signed to a protection frequency. On the receive side each protection fre-
quency can be assigned to one or more signal outputs. This function is
only available with the coded tripping (CT) feature.
This mode offers the transmission of two double systems. One is trans-
mitted in the fast permissive transfer trip, the other in the direct transfer
trip using the CT feature.
Edition p3_3_2x 08/09
SWT 3000 Equipment Manual
© SIEMENS AG 2008