ABB REL650 Product Manual page 25

Line distance protection REL650 ANSI
Product version: 1.3
Function commands for IEC60870-5-103, I103CMD,
I103IEDCMD, I103URSCMD, I103GENCMD, I103POSCMD
IEC60870–5–103 function and command logic blocks are
available for configuration of the IED. The output signals are
predefined or user defined depending on selected function block.
10. Scheme communication
Scheme communication logic with delta based blocking scheme
signal transmit ZCPSCH (85)
To achieve instantaneous fault clearance for all line faults, scheme
communication logic is provided. All types of communication
schemes for permissive underreaching, permissive overreaching,
blocking, delta based blocking, unblocking and intertrip are
available.
Current reversal and WEI logic for distance protection, 3-phase
ZCRWPSCH (85)
The current reversal function is used to prevent unwanted
operations due to current reversal when using permissive
overreach or unblock protection or unblocking schemes in
application with parallel lines.
The weak-end infeed logic is used in cases where the apparent
power behind the protection can be too low to activate the
distance protection function. When activated, received carrier
signal together with local undervoltage criteria and no reverse
zone operation gives an instantaneous three-phase trip. The
received signal is also echoed back during 200 ms to accelerate
the sending end.
Current reversal and WEI logic for distance protection, phase
segregated ZCWSPSCH (85)
The current reversal function is used to prevent unwanted
operations due to current reversal when using permissive
overreach protection schemes in application with parallel lines
when the overreach from the two ends overlap on the parallel line.
The weak-end infeed logic is used in cases where the apparent
power behind the protection can be too low to activate the
distance protection function. When activated, received carrier
signal together with local undervoltage criteria and no reverse
zone operation gives an instantaneous one- or three-phase trip.
The received signal is also echoed back during 200 ms to
accelerate the sending end.
Local acceleration logic ZCLCPLAL
To achieve fast clearing of faults on the whole line, when no
communication channel is available, local acceleration logic
ZCLCPLAL can be used. This logic enables fast fault clearing and
re-closing during certain conditions, but naturally, it can not fully
replace a communication channel.
ABB
The logic can be controlled either by the autorecloser (zone
extension) or by the loss-of-load current (loss-of-load
acceleration).
Scheme communication logic for residual overcurrent protection
ECPSCH (85)
To achieve fast fault clearance of ground faults on the part of the
line not covered by the instantaneous step of the residual
overcurrent protection, the directional residual overcurrent
protection can be supported with a logic that uses
communication channels.
In the directional scheme, information of the fault current direction
must be transmitted to the other line end. With directional
comparison, a short operate time of the protection including a
channel transmission time, can be achieved. This short operate
time enables rapid autoreclosing function after the fault
clearance.
The communication logic module for directional residual current
protection enables blocking as well as permissive under/
overreaching, and unblocking schemes. The logic can also be
supported by additional logic for weak-end infeed and current
reversal, included in Current reversal and weak-end infeed logic
for residual overcurrent protection ECRWPSCH (85) function.
Current reversal and weak-end infeed logic for residual
overcurrent protection ECRWPSCH (85)
The Current reversal and weak-end infeed logic for residual
overcurrent protection ECRWPSCH (85) is a supplement to
Scheme communication logic for residual overcurrent protection
ECPSCH (85).
To achieve fast fault clearing for all ground faults on the line, the
directional ground-fault protection function can be supported
with logic that uses communication channels.
The 650 series IEDs have for this reason available additions to
scheme communication logic.
If parallel lines are connected to common busbars at both
terminals, overreaching permissive communication schemes can
trip unselectively due to fault current reversal. This unwanted
tripping affects the healthy line when a fault is cleared on the other
line. This lack of security can result in a total loss of
interconnection between the two buses. To avoid this type of
disturbance, a fault current reversal logic (transient blocking logic)
can be used.
Permissive communication schemes for residual overcurrent
protection can basically operate only when the protection in the
remote IED can detect the fault. The detection requires a
sufficient minimum residual fault current, out from this IED. The
fault current can be too low due to an opened breaker or high-
positive and/or zero-sequence source impedance behind this
1MRK 506 337-BUS B
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