Weak-end infeed logic
Set
OperationWEI to Echo, to activate the weak-end infeed function with only echo function.
Set
OperationWEI to Echo&Trip to obtain echo with trip.
Set
tPickUpWEI to 10 ms, a short delay is recommended to avoid that spurious carrier received
signals will activate WEI and cause unwanted communications.
Set the voltage criterion
UPP< and UPE< for the weak-end trip to 70% of the system base
voltage
UBase. The setting should be below the minimum operate voltage of the system but
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.
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.
15.5
Local acceleration logic ZCLCPSCH
SEMOD52894-1 v4
15.5.1
Identification
M14860-1 v4
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Local acceleration logic
ZCLCPSCH
-
-
15.5.2
Application
M13821-3 v3
The local acceleration logic (ZCLCPSCH) is used in those applications where conventional
teleprotection scheme is not available (no communication channel), but the user still require
fast clearance for faults on the whole line.
This logic enables fast fault clearing during certain conditions, but naturally, it can not fully
replace a teleprotection scheme.
The logic can be controlled either by the autorecloser (zone extension) or by the loss-of-load
current (loss-of-load acceleration).
The loss-of-load acceleration gives selected overreach zone permission to operate
instantaneously after check of the different current criteria. It can not operate for three-phase
faults.
15.5.3
Setting guidelines
M13854-4 v3
The parameters for the local acceleration logic functions are set via the local HMI or PCM600.
Set
ZoneExtension to On when the first trip from selected overreaching zone shall be
instantaneous and the definitive trip after autoreclosure a normal time-delayed trip.
Set
LossOfLoad to On when the acceleration shall be controlled by loss-of-load in healthy
phase(s).
1MRK 505 343-UEN B
Section 15
Scheme communication
615
Application manual
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