Hitachi Relion 670 Series Applications Manual page 173

1MRK511407-UUS Rev. N
Common base IED values for primary current IBase and primary voltage VBase are set in the global
base values for settings function GBASVAL. The GlobalBaseSel is used to select GBASVAL for the
reference of base values.
FTAQFVR (81A) used to protect a turbine:
Frequency during start-up and shutdown is normally not calculated, consequently the protection function
is blocked by CB position, parameter CBCheck enabled. If the generator supply any load when CB is in
open position e.g. excitation equipment and auxiliary services this may be considered as normal
condition and CBCheck is ignored when the load current is higher then the set value of
PickupCurrentLevel. Set the current level just above minimum load.
EnaVoltCheck set to Disable.
tCont: to be coordinated to the grid requirements.
tAccLimit, FreqHighLimit and FreqLowLimit setting is derived from the turbine manufacturer's operating
requirements, note that FreqLowLimit setting must always be lower than the set value of FreqHighLimit.
FTAQFVR (81A) used to protect a generator:
Frequency during start-up and shutdown is normally not calculated, consequently the protection function
is blocked by CB position, parameter CBCheck enabled.
PickupCurrentLevel set to Disable.
EnaVoltCheck set to Enable, voltage and frequency limits set according to the generators manufacturer's
operating requirements. Voltage and frequency settings should also be coordinated with the pickup
values for over and underexcitation protection.
tCont: to be coordinated to the grid requirements.
tAccLimit, FreqHighLimit and FreqLowLimit setting is derived from the generator manufacturer's
operating requirements.
Phasor measurement unit RES670
Application manual
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Section 10
Frequency protection
167