Load voltage adjustment (LVA)
LVAConst1
: Setting of the first load voltage adjustment value. This adjustment of the target
value
USet
is given in percent of
UBase
.
LVAConst2
: Setting of the second load voltage adjustment value. This adjustment of the target
value
USet
is given in percent of
UBase
.
LVAConst3
: Setting of the third load voltage adjustment value. This adjustment of the target
value
USet
is given in percent of
UBase
.
LVAConst4
: Setting of the fourth load voltage adjustment value. This adjustment of the target
value
USet
is given in percent of
UBase
.
VRAuto
: Setting of the automatic load voltage adjustment. This adjustment of the target value
USet
is given in percent of
UBase
, and it is proportional to the load current with the set value
reached at the nominal current
I2Base
.
RevAct
OperationRA
: This setting enables/disables the reverse action partial blocking function.
tRevAct
: After the reverse action has picked up, this time setting gives the time during which
the partial blocking is active.
RevActLim
: Current threshold for the reverse action activation. This is just one of two criteria
for activation of the reverse action partial blocking.
Tap changer control (TCCtrl)
Iblock
: Current setting of the over current blocking function. In case, the transformer is
carrying a current exceeding the rated current of the tap changer for example, because of an
external fault. The tap changer operations shall be temporarily blocked. This function typically
monitors the three phase currents on the HV side of the transformer.
DayHuntDetect
: Setting of the number of tap changer operations required during the last 24
hours (sliding window) to activate the signal DAYHUNT
HourHuntDetect
: Setting of the number of tap changer operations required during the last
hour (sliding window) to activate the signal HOURHUNT
tWindowHunt
: Setting of the time window for the window hunting function. This function is
activated when the number of contradictory commands to the tap changer exceeds the
specified number given by
NoOpWindow
within the time
tWindowHunt
.
NoOpWindow
: Setting of the number of contradictory tap changer operations (RAISE, LOWER,
RAISE, LOWER etc.) required during the time window
tWindowHunt
to activate the signal
HUNTING.
Power
P>
: When the active power exceeds the value given by this setting, the output PGTFWD will be
activated after the time delay
tPower
. It shall be noticed that the setting is given with sign,
which effectively means that a negative value of
P>
means an active power greater than a value
in the reverse direction. This is shown in figure
164 where a negative value of
P>
means pickup
for all values to the right of the setting. Reference is made to figure 159 for definition of
forward and reverse direction of power through the transformer.
1MRK 511 358-UEN A Section 13
Control
329
Application manual
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