Current Reversal And Weak-End Infeed Logic Crwpsch - ABB RELION REX640 Technical Manual

1MRS759142 C
5.12
5.12.1
5.12.2
5.12.3
5.12.4
REX640
Technical Manual
Current reversal and weak-end infeed logic
CRWPSCH
Identification
Function description
Current reversal and weak-end infeed
logic
Function block
GUID-468E0D76-A57D-4B17-B223-9C98C5900152 V1 EN
Figure 629: Function block
Functionality
The current reversal and weak-end infeed logic function CRWPSCH can be used
when the scheme communication logic DSOCPSCH requires additional logics to
operate correctly in all power system conditions.
In parallel feeder applications, the fault current direction on the healthy feeder can
change when the circuit breaker on the faulty feeder opens to clear the fault. This can
lead to an unwanted operation of the distance protection on the healthy parallel feeder
when DSOCPSCH is used with the permissive overreach scheme. The main purpose
of the current reversal logic is to prevent such unwanted operations.
The permissive communication schemes can operate only when the protection in the
remote terminal can detect the fault. This detection requires sufficient minimum fault
current. If such current is not available due to a too weak remote end source, the weak-
end infeed logic can be used to overcome the situation and trip the remote end breaker.
Analog channel configuration
CRWPSCH has one analog group input which must be properly configured.
Table 1090: Analog inputs
Input
U3P
Protection related functions
IEC 61850 IEC 60617
identification identification
CRWPSCH CLCRW
Description
Three-phase voltages
Section 5
ANSI/IEEE C37.2
device number
85 21CREV,WEI
1169