Hitachi Relion 670 Series Applications Manual page 292

Section 13
Scheme communication
GlobalBaseSel: Selects the global base value group used by the function to define IBase, UBase and
SBase. Note that this function will only use IBase and UBase values.
13.2.3.1 Current reversal logic
Set CurrRev to On to activate the function.
Set tDelayRev timer of 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 delays the fault clearing
time in case of a fault 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 minimum sum of breaker operate time +
communication delay time, but with a minimum of 20 ms.
13.2.3.2 Weak-end infeed logic
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.
The tPickUpWEI is the on-time delay to activate the weak-end infeed function. 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 operate voltage of the system but above the voltage that
occurs for fault on the protected line. The fault condition is detected, if the phase-to-phase voltage is
below the UPP< set value and/or if the phase-to-earth voltage is below the UPN< set value.
13.3 Scheme communication logic for residual overcurrent
protection ECPSCH
13.3.1 Function revision history
Document
revision
B
C
D
E
F
G
H
J
K
K
Table continues on next page
286
The forward zone timer must be set longer than the tDelayRev set value.
Product History
revision
2.2.1 -
2.2.2 -
2.2.2
2.2.2 -
2.2.3 -
2.2.3 -
2.2.3 -
2.2.4 -
2.2.4 -
2.2.4
© 2017 - 2023 Hitachi Energy. All rights reserved
1MRK506375-UEN Rev. N
M13856-6 v7
M13856-10 v8
IP14711-1 v2
GUID-F53CEDFF-DD1E-4FC2-A8AF-85DD40DBF71B v2
Railway application RER670
Application manual