ABB RET670 Applications Manual page 695

1MRK504116-UUS C
Application manual
MeasMode: Selection of single phase, or phase-phase, or positive sequence quantity to
be used for voltage and current measurement on the LV-side. The involved phases are
also selected. Thus, single phase as well as phase-phase or three-phase feeding on the
LV-side is possible but it is commonly selected for current and voltage.
Q1, Q2 and Q3: MVAr value of a capacitor bank or reactor that is connected between
the power transformer and the CT, such that the current of the capacitor bank (reactor)
needs to be compensated for in the calculation of circulating currents. There are three
independent settings Q1, Q2 and Q3 in order to make possible switching of three steps
in a capacitor bank in one bay.
TotalBlock: When this setting is Enabled, TR1ATCC (90) or TR8ATCC (90) function
that is, the voltage control is totally blocked for manual as well as automatic control.
AutoBlock: When this setting is Enabled, TR1ATCC (90) or TR8ATCC (90) function
that is, the voltage control is blocked for automatic control.
Operation
FSDMode: This setting enables/disables the fast step down function. Enabling can be
for automatic and manual control, or for only automatic control alternatively.
tFSD: Time delay to be used for the fast step down tapping.
Voltage
VSet: Setting value for the target voltage, to be set in per cent of VBase.
VDeadband: Setting value for one half of the outer deadband, to be set in per cent of
VBase. The deadband is symmetrical around VSet, see section
transformer", figure 277. In that figure VDeadband is equal to DV.
control for a single
The setting is normally selected to a value near the power transformer's tap changer
voltage step (typically 75 - 125% of the tap changer step).
VDeadbandInner: Setting value for one half of the inner deadband, to be set in per cent
of VBase. The inner deadband is symmetrical around VSet, see section
voltage control for a single
equal to DV
. The setting shall be smaller than VDeadband. Typically the inner
in
deadband can be set to 25-70% of the VDeadband value.
Vmax: This setting gives the upper limit of permitted busbar voltage (see section
"Automatic voltage control for a single
VBase. If OVPartBk is set to Auto&ManBlock, then busbar voltages above Vmax will
result in a partial blocking such that only lower commands are permitted.
Vmin This setting gives the lower limit of permitted busbar voltage (see section
"Automatic voltage control for a single
transformer",figure 277. In that figure VDeadbandInner is
transformer", figure 277). It is set in per cent of
transformer", figure 277). It is set in per cent of
Section 3
IED application
"Automatic voltage
"Automatic
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