signal would block the operation of the distance protection at the remote line end and in
this way prevents the correct operation of a complete protection scheme.
•
A separate direct intertrip channel must be arranged from remote end when a trip or
accelerated trip is given there. The intertrip receive signal is connect to input CRL.
•
The WEI function shall be set to
WEI=Echo&Trip. The WEI function block will then give
phase selection and trip the local breaker.
Avoid using WEI function at both line ends. It shall only be activated at the weak-end.
15.3.3
Setting guidelines
IP15024-1 v1
M13856-4 v5
The parameters for the current reversal logic and the weak-end infeed logic (WEI) function are
set via the local HMI or PCM600.
Common base IED values for primary current (
IBase), primary voltage (UBase) and primary
power (
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.
15.3.3.1
Current reversal logic
M13856-6 v5
Set
CurrRev to On to activate the function.
Set
tDelayRev timer at the maximum reset time for the communication equipment that gives
the carrier receive (CRL) signal plus 30 ms. A minimum setting of 40 ms is recommended,
typical 60 ms.
A long
tDelayRev setting increases security against unwanted tripping, but delay the fault
clearing in case of a fault developing from one line that evolves to the other one. The
probability of this type of fault is small. Therefore set
tDelayRev with a good margin.
Set the pick-up delay
tPickUpRev to <80% of the breaker operate time, but with a minimum of
20 ms.
15.3.3.2
Weak-end infeed logic
M13856-10 v6
Set
WEI to Echo, to activate the weak-end infeed function with only echo function.
Set
WEI to Echo&Trip to obtain echo with trip.
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.
Section 15
1MRK 505 343-UEN B
Scheme communication
612
Application manual
Summary of Contents for Relion 670 series
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