Line Differential Protection L4Cpdif; Possible Configurations - ABB Relion 670 Series Application Manual

Section 4
Analog and binary signal transfer for line differential protection
IED
IEC15000451 V2 EN-US
Figure 29: One three–winding transformer in the protected zone
4.6.2

Line differential protection L4CPDIF

4.6.2.1

Possible configurations

The simplest and most common configuration is the protection of a conventional two-end
power line (see Figure 30). Circuit breakers (CBs) at both ends can be included in the protected
zone depending on their positions relative to the current transformers (CTs).
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IEC05000039 V3 EN-US
Figure 30: Two-end power line with one CB and one CT group at each end
It is also possible to protect a two-end power line that has two CB and CT groups at one end
and one CB and CT group at the other end (see Figure 31). All currents from the three CTs must
be fed separately to L4CPDIF which processes the measured currents independently from each
other. Summing up the CTs' secondary currents at the end with two CB and CT groups is not
allowed. CBs at both ends can be included in the protected zone depending on their positions
relative to the CTs.
IEC15000459 V1 EN-US
Figure 31:
If there are two CB and CT groups at both ends of a two-end power line, information on
currents must be fed to all four current inputs of both IEDs. Current values at the remote end
are obtained via a communication channel as shown in Figure 32. Summing up the CTs'
secondary currents at the end with two CB and CT groups is not allowed. CBs at both ends can
be included in the protected zone depending on their positions relative to the CTs.
30
A
Communication channel
Two-end power line with two CB and CT groups at one end
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Protected zone
T
T
Protected zone
IEC15000459-1-en.vsd
1MRK 505 382-UEN E
B
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IEC15000451-2-en.vsdx
GUID-566BF5F0-3E2D-42D8-9D53-BCAFB7F0BEA9 v2
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IEC05000039-3-en.vsd
Communication set-up, 670/650 series
Application Guide