Set
tPickUpWEI
to
10
ms, a short delay is recommended to avoid that spurious carrier received
signals will activate WEI and cause unwanted carrier send (ECHO) signals.
Set the voltage criterion
UPP<
and
UPN<
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.
14.3 Local acceleration logic ZCLCPSCH
SEMOD52894-1 v4
14.3.1 Identification
M14860-1 v4
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Local acceleration logic ZCLCPSCH - -
14.3.2 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.
14.3.3 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).
LoadCurr
must be set below the current that will flow on the healthy phase when one or two of
the other phases are faulty and the breaker has opened at remote end (three-phase). Calculate
the setting according to equation
130.
Section 14 1MRK 511 358-UEN A
Scheme communication
350
Application manual
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