IED-A
IED-B
IED-C
IEC16000077-1-en.vsd
3-end differential protection with two communication links
Ldcm312
Ldcm312
Ldcm313
Ldcm312
IEC16000077 V1 EN-US
Figure 224: Three-end differential protection with two communication links
If the LDCM is in 2Mbit mode, you can send the three local currents as well as the three remote
currents from the other links by configuring the transmitters in IED-B:
1.
Ldcm312 transmitter sends the local currents and the three currents received by Ldcm313.
2.
Ldcm313 transmitter sends the three local currents and the three currents received from
Ldcm312.
As a result, six currents are received in IED-A and IED-C. These currents can be connected to
the protection function together with the local three currents.
In order to forward the logic signals (for example, inter-trip or inter-block)
between IED-A and IED-C, the setting
LinkForwarded should be defined. In IED-
B, it is set to
LDCM313 for Ldcm312 and to LDCM312 for ldcm313.
This setup results in a master-master-master configuration, but without the benefit of
reverting to a slave-master-slave configuration in case of a communication link interruption. In
case of a communication link interruption, all three IEDs would be blocked.
18.1.2.1
Communication hardware solutions
M12844-11 v7
The LDCM (Line Data Communication Module) has an optical connection such that two IEDs
can be connected over a direct fiber (multimode), as shown in figure
IEEE/ANSI C37.94. The distance with this solution is typical 110 km.
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
LD
CM
en06000519-2.vsd
IEC06000519 V2 EN-US
Figure 225: Direct fiber optical connection between two IEDs with LDCM
The LDCM can also be used together with an external optical to galvanic G.703 converter or
with an alternative external optical to galvanic X.21 as shown in figure
. These solutions are
aimed for connections to a multiplexer, which in turn is connected to a telecommunications
transmission network (for example PDH).
Section 18
1MRK 505 370-UEN D
Remote communication
420
Busbar protection REB670
Application manual
Summary of Contents for REB670 Series
Page 1: ...Relion 670 SERIES Busbar protection REB670 Version 2 2 IEC Application manual ...
Page 2: ......
Page 22: ...16 ...
Page 64: ...58 ...
Page 226: ...220 ...
Page 244: ...238 ...
Page 358: ...352 ...
Page 392: ...386 ...
Page 398: ...392 ...
Page 436: ...430 ...
Page 454: ...448 ...
Page 466: ...460 ...
Page 474: ...468 ...
Page 475: ...469 ...