ABB RELION RET670 User Manual

tSecurity: The absence of CRG signal for a time duration of tSecurity is considered as
CR signal.
16.6 Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH
(85)
IP14365-1 v4
16.6.1 Identification
M14883-1 v2
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Current reversal and weak-end infeed
logic for residual overcurrent protection
ECRWPSCH - 85
16.6.2 Application
IP15041-1 v1
16.6.2.1 Fault current reversal logic
M15285-3 v7
Figure 391 and figure 392 show a typical system condition, which can result in a fault
current reversal.
Assume that fault is near the B1 breaker. B1 Relay sees the fault in Zone1 and A1 relay
identifies the fault in Zone2.
Note that the fault current is reversed in line L2 after the breaker B1 opening.
It can cause an unselective trip on line L2 if the current reversal logic does not block
the permissive overreaching scheme in the IED at B2.
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 391: Current distribution for a fault close to B side when all breakers are
closed
Section 16 1MRK 504 163-UUS A
Scheme communication
834 Transformer protection RET670 2.2 ANSI
Application manual

ABB RELION RET670 Specifications

General

Brand	ABB
Model	RELION RET670
Category	Protection Device
Language	English