These signals can be used for informational and also for transformer related logics and monitoring
usage. For example constant long duration heavy overloading may cause the transformer oil ageing
and thus the maintenance should be applied before scheduled in order to prevent possible problems in
the transformer.
Settings and signals
Settings of the transformer status monitor (TRF) function are mostly shared with transformer protection
functions in the transformer module of the IED. In following table are shown the functions which use
these settings also.
Table. 5.4.16. - 137. Settings of the TRF function.
Name
Range
Step
Default
Funcs.
Description
Transformer
nominal
MVA
0.1...500.0MVA 0.1MVA 1.0MVA
All
Nominal MVA of transformer. This value is used to
calculate nominal currents of HV, and LV side.
HV side
nominal
voltage
0.1…500.0kV
0.1kV
110.0kV
All
HV side nominal voltage of the transformer. This value
is used to calculate nominal currents of HV side.
LV side
nominal
voltage
0.1…500.0kV
0.1kV
110.0kV
All
LV side nominal voltage of the transformer. This value
is used to calculate nominal currents of LV side.
Transformer
Zk%
0.01…25.00%
0.01%
3.00%
Info
Transformer short circuit impedance in %. Used for
calculation of the short circuit currents
Transformer
nom. freq
10…75Hz
1Hz
50Hz
Info
Transformer nominal frequency. Used for calculation of
transformer nominal short circuit inductance.
Transf. Vect.
group
0:Manual
1:Yy0
2:Yyn0
3:YNy0
4:YNyn0
5:Yy6
6:Yyn6
7:YNy6
8:YNyn6
9:Yd1
10:YNd1
11:Yd7
12:YNd7
13:Yd11
14:YNd11
15:Yd5
16:YNd5
17:Dy1
18:Dyn1
19:Dy7
20:Dyn7
21:Dy11
22:Dyn11
23:Dy5
24:Dyn5
25:Dd0
26:Dd6
-
1:Yy0
TRF,
DIFF
Selection of the transformer vector group. Selection
values from 1 to 26 are prede ned so that just by
selecting correct vector group the scaling and vector
matching is applied in the relay automatically.
In the prede nitions it is assumed that the HV side is
connected to CT1 module and LV side is in CT2
module.
If the protected transformer vector group is not found
in the prede ned list, manual set can be applied by
selecting 0: Manual set.
HV side Star
or Zigzag /
Delta
0:Star/Zigzag
1:Delta
-
0:Star/Zigzag TRF,
DIFF
Selection of the HV side connection, star or zigzag or
delta. Selection is visible only if vector group is set to
“0:Manual set”
HV side
grounded
0:Not grounded
1:Grounded
-
0:Not
grounded
TRF,
DIFF
Selection whether the zero sequence compensation
should be applied into HV side currents calculation.
Selection is visible only if vector group is set to
“0:Manual set”
HV side lead
or lag LV
0:Lead
1:Lag
-
0:Lead
TRF,
DIFF
Selection for HV side leads or lags LV side. Selection is
visible only if vector group is set to “0:Manual set”
AQ-T257
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
132