ABB Relion 670 Series Applications Manual page 231

1MRK 511 401-UEN Rev. K
in the secondary circuits. The setting is normally done at site by evaluating the differential
voltage achieved as a service value for each phase. The factor is defined as U2 ·
be equal to the U1 voltage. Each phase has its own ratio factor.
UDTrip : The voltage differential level required for tripping is set with this parameter. For
application on capacitor banks the setting will depend of the capacitor bank voltage and the
number of elements per phase in series and parallel. Capacitor banks must be tripped before
excessive voltage occurs on the healthy capacitor elements. The setting values required are
normally given by the capacitor bank supplier. For other applications it has to be decided case
by case. For fuse supervision normally only the alarm level is used.
tTrip : The time delay for tripping is set by this parameter. Normally, the delay does not need to
be so short in capacitor bank applications as there is no fault requiring urgent tripping.
tReset : The time delay for reset of tripping level element is set by this parameter. Normally, it
can be set to a short delay as faults are permanent when they occur.
For the advanced users following parameters are also available for setting. Default values are
here expected to be acceptable.
U1Low : The setting of the undervoltage level for the first voltage input is decided by this
parameter. The proposed default setting is 70%.
U2Low : The setting of the undervoltage level for the second voltage input is decided by this
parameter. The proposed default setting is 70%.
tBlock : The time delay for blocking of the function at detected undervoltages is set by this
parameter.
UDAlarm : The voltage differential level required for alarm is set with this parameter. For
application on capacitor banks the setting will depend of the capacitor bank voltage and the
number of elements per phase in series and parallel. Normally values required are given by
capacitor bank supplier.
For fuse supervision normally only this alarm level is used and a suitable voltage level is 3-5% if
the ratio correction factor has been properly evaluated during commissioning.
For other applications it has to be decided case by case.
tAlarm : The time delay for alarm is set by this parameter. Normally, few seconds delay can be
used on capacitor banks alarm. For fuse failure supervision (SDDRFUF) the alarm delay can be
set to zero.
9.5 Loss of voltage check LOVPTUV
9.5.1 Identification
Function description
Loss of voltage check
9.5.2 Application
The trip of the circuit breaker at a prolonged loss of voltage at all the three phases is normally
used in automatic restoration systems to facilitate the system restoration after a major
blackout. Loss of voltage check (LOVPTUV) generates a TRIP signal only if the voltage in all the
three phases is low for more than the set time. If the trip to the circuit breaker is not required,
Bay control REC670
Application manual
IEC 61850
identification
LOVPTUV
© Copyright 2017 Hitachi Power Grids. All rights reserved
IEC 60617 ANSI/IEEE C37.2
identification device number
- 27
Section 9
Voltage protection
RFLx and shall
SEMOD171868-1 v2
SEMOD171954-2 v2
SEMOD171876-4 v3
225