ABB RET670 Applications Manual page 119

1MRK504116-UUS C
Application manual
Setting parameter
TconfigForW1
TconfigForW2
LocationOLTC1
Other Parameters
1)
To compensate for delta connected CTs
2)
Zero-sequence current is already removed by connecting main CTs in delta
Delta-wye connected power transformer without tap charger
Single line diagrams for two possible solutions for such type of power transformer with
all relevant application data are given in figure 28.
CT 400/5
Wye
60 MVA
115/24.9 kV
Dyn1
(D Y)
AB
CT 1500/5
Wye
ANSI06000555 V1 EN
Figure 28: Two differential protection solutions for delta-wye connected power
transformer
For this particular power transformer the 115 kV side phase-to-ground no-load
voltages lead by 30° the 24.9 kV side phase-to-ground no-load voltages. Thus when
external phase angle shift compensation is done by connecting main 24.9 kV CTs in
Select value for both solution 1
(wye connected CT)
No
No
Not used
Not relevant for this application.
Use default value.
CT 400/5
60 MVA
115/24.9 kV
Dyn1
(D Y)
AB
CT 1500/5
Section 3
IED application
Selected value for both solution 2
(delta connected CT)
No
No
Not used
Not relevant for this application.
Use default value.
Wye
in Delta
(DAB)
en06000555_ansi.vsd
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