ABB Relion 670 Series Applications Manual page 427

1MRK 511 401-UUS F
breaker in B. To cope with this situation, a selectable weak-end infeed logic is provided for the
permissive overreaching scheme.
Strong
source
A
ANSI99000054 V1 EN-US
Figure 202: Initial condition for weak-end infeed
15.5.3 Setting guidelines
The parameters for the current reversal and weak-end infeed logic for residual overcurrent
protection function are set via the local HMI or PCM600.
Common base IED values for primary current (
SBase ) are set in a Global base values for settings function GBASVAL.
(
GlobalBaseSel : It is used to select a GBASVAL function for reference of base values.
15.5.3.1 Current reversal
The current reversal function is set on or off by setting the parameter
Disabled . Time delays shall be set for the timers tPickUpRev and tDelayRev .
tPickUpRev is chosen shorter (<80%) than the breaker opening time, but minimum 20 ms.
tDelayRev is chosen at a minimum to the sum of protection reset time and the communication
reset time. A minimum
The reset time of the directional residual overcurrent protection (EF4PTOC) is typically 25 ms. If
other type of residual overcurrent protection is used in the remote line end, its reset time should
be used.
The signal propagation time is in the range 3 – 10 ms/km for most types of communication media.
In communication networks small additional time delays are added in multiplexers and repeaters.
Theses delays are less than 1 ms per process. It is often stated that the total propagation time is
less than 5 ms.
When a signal picks-up or drops out there is a decision time to be added. This decision time is
highly dependent on the interface between communication and protection used. In many cases an
external interface (teleprotection equipment) is used. This equipment makes a decision and gives
a binary signal to the protection device. In case of analog teleprotection equipment typical
decision time is in the range 10 – 30 ms. For digital teleprotection equipment this time is in the
range 2 – 10 ms.
If the teleprotection equipment is integrated in the protection IED the decision time can be
slightly reduced.
The principle time sequence of signaling at current reversal is shown.
Bay control REC670
Application manual
CLOSED
LINE 1
tDelayRev setting of 40 ms is recommended.
© Copyright 2017 ABB. All rights reserved
Weak
CLOSED
source
FAULT
B
en99000054_ansi.vsd
IBase ), primary voltage (VBase) and primary power
Section 15
Scheme communication
IP15042-1 v1
M13933-4 v5
M13933-6 v5
CurrRev to Enabled or
421