ABB RED650, Applications Manual

Page: 300 / 454

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.
Protection
Function
Protection
Function
Tele-
Protection
Equipment
Tele-
Protection
Equipment
Tele-
communication
System
CS from the
protection
function, operate
and reset time
CS initiation to
the
communication
system, operate
and reset time
CS propagation,
propagation
CR selection and
decision, operate
and reset time
CR to the
protection
function, operate
and reset time
Time
Fault
occurs
Protection
pick-up CS initiation
CR to
teleprot.
eq.
CR to
prot.
func
Fault current
reversal
Sending
protection
reset
CS to
communication
drop
CR
reception
drop
CR to
prot.
func
drop
Minimum setting of tDelay
IEC05000536-2-en.vsd
IEC05000536 V2 EN-US
Figure 127: Time sequence of signaling at current reversal
13.5.3.2 Weak-end infeed
M13933-12 v6
The weak-end infeed can be set by setting the parameter WEI to Off , Echo or Echo
& Trip . Operating zero sequence voltage when parameter WEI is set to Echo &
Trip is set with 3U0>.
The zero sequence voltage for a fault at the remote line end and appropriate fault
resistance is calculated.
To avoid unwanted trip from the weak-end infeed logic (if spurious signals should
occur), set the operate value of the broken delta voltage level detector (3U0) higher
than the maximum false network frequency residual voltage that can occur during
normal service conditions. The recommended minimum setting is two times the
false zero-sequence voltage during normal service conditions.
Section 13
1MRK 505 393-UEN B
Scheme communication
294 Line differential protection RED650 2.2 IEC
Application manual