Current Reversal And Weak-End Infeed Logic For Phase Segregated Communication Zc1Wpsch; Identification; Application - ABB RELION 650 Series Applications Manual

Section 13
Scheme communication
tPickUpWEI to 10 ms, a short delay is recommended to avoid that spurious carrier received
Set
signals will activate WEI and cause unwanted carrier send (ECHO) signals.
Set the voltage criterion
voltage
above the voltage that occurs for fault on the protected line. The phase-to-phase elements
must be verified to not operate for phase to earth faults.
13.3 Current reversal and weak-end infeed logic for phase
segregated communication ZC1WPSCH
13.3.1

Identification

Function description
Current reversal and weak-end
infeed logic for phase segregated
communication
13.3.2

Application

Current reversal logic
If parallel lines are connected to common buses at both terminals, overreaching permissive
communication schemes can trip unselectable due to current reversal. The unwanted tripping
affects the healthy line when a fault is cleared on the other line. This lack of security results in a
total loss of interconnection between the two buses.
To avoid this kind of disturbances, fault current reversal logic (transient blocking logic) can be
used.
The unwanted operations that might occur can be explained by looking into
Figure 134. Assume that the fault has been taken place close to breaker B1. At first, 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.
IEC14000002 V1 EN-US
Figure 133: 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
260
UPP< and UPN< for the weak-end trip to 70% of the system base
UBase . The setting should be below the minimum operate voltage of the system but
When single phase tripping is required a detailed study of the voltages at
phase-to-phase respectively phase-to-earth faults, at different fault locations,
is normally required.
L1
A1
L2
A2
IEC 61850 IEC 60617
identification identification
ZC1WPSCH
B1
B2
IEC14000002-1-en.vsd
1MRK 505 363-UEN A
ANSI/IEEE C37.2
device number
- 85
Figure 133
Application manual
SEMOD155635-1 v2
SEMOD156467-2 v2
SEMOD156558-1 v1
SEMOD156537-5 v4
and