ABB RELION RET670, Applications Manual

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16.3 Current reversal and Weak-end infeed logic for
distance protection 3-phase ZCRWPSCH (85)
IP15751-1 v4
16.3.1 Identification
M15073-1 v5
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Current reversal and weak-end infeed
logic for distance protection 3-phase
ZCRWPSCH - 85
16.3.2 Application
IP15023-1 v1
16.3.2.1 Current reversal logic
M13895-4 v6
To avoid this kind of disturbances, a fault current reversal logic (transient blocking
logic) can be used.
The unwanted operations that might occur can be explained by looking into Figure 387
and Figure 388 . Initially the protection A2 at A side will detect a fault in forward
direction and send a communication signal to the protection B2 at remote end, which is
measuring a fault in reverse direction.
en99000043_ansi.vsd
Strong
source
LINE 1
LINE 2
A:1
A:2
B:1
B:2
A B
Weak
source
FAULT
CLOSED
CLOSED
CLOSED
CLOSED
ANSI99000043 V1 EN-US
Figure 387: Current distribution for a fault close to B side when all breakers are
closed
When the breaker B1 opens for clearing the fault, the fault current through B2 bay will
invert. If the communication signal has not reset at the same time as the distance
protection function used in the teleprotection scheme has switched on to forward
direction, we will have an unwanted operation of breaker B2 at B side.
Section 16
1MRK 504 163-UUS A
Scheme communication
826 Transformer protection RET670 2.2 ANSI
Application manual