ABB Relion 670 Series Applications Manual page 397

1MRK 511 358-UUS A
14.3 Local acceleration logic ZCLCPSCH
14.3.1 Identification
Function description
Local acceleration logic
14.3.2 Application
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
The parameters for the local acceleration logic functions are set via the local HMI or PCM600.
ZoneExtension to Enabled when the first trip from selected overreaching zone shall be
Set
instantaneous and the definitive trip after autoreclosure a normal time-delayed trip.
LossOfLoad to Enabled when the acceleration shall be controlled by loss-of-load in healthy
Set
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 131.
LoadCurr
EQUATION1320 V1 EN-US
where:
ILoadmin is the minimum load current on the line during normal operation conditions.
Application manual
When single pole tripping is required a detailed study of the voltages at phase-to-
phase respectively phase-to-ground faults, at different fault locations, is normally
required.
×
0.5 I
Load
min
=
I
Base
IEC 61850 IEC 60617
identification identification
ZCLCPSCH -
Scheme communication
ANSI/IEEE C37.2
device number
-
(Equation 131)
Section 14
SEMOD52894-1 v4
M14860-1 v4
M13821-3 v3
M13854-4 v3
391