Delta C1000 Operation And Installation Manual page 84

Appendix C: Delta MV Transformer and Auxiliary Power transformer Application Note
B.1 Technical requirement of two-winding transformer
- The voltage impedance should line between 4.0-6.6%
- The vector grouping of two-winding transformer can be Dy11, YNd11 or Dd0
* Please use DC+ to earth ground or DC- to earth ground if YNd11 is applied.
MV
U1
V1
W1
Dy11
B.2 Technical requirement of three-winding transformer
- The impedance voltage between each low voltage winding and high voltage should lie
between 4.0-6.6%.
- The impedance voltage between two low voltage winding should lie between 9~11%.
- The vector grouping of three-winding transformer can be Dy11y11, YNd11d11, Dd0d0
or Dyn1yn1.
- If Dyn11yn11 or Dyn1yn1 does apply, to left both the Neutral point of low voltage
winding unconnected and ungrounding.
* Please use DC+ to earth ground or DC- to earth ground if YNd11d11 is applied.
MV
U1
V1
W1
N1
YNd11d11
MV
LV
U1
V1
W1
N1
YNd11
MV
LV
U2
V2
U1
W2
V1
U3
W1
V3
W3
LV
U2
V2
W2
LV
U2
V2
W2
U3
V3
W3
Dy11y11
84
MV
U1
V1
W1
Dd0
MV
U1
V1
W1
Dd0d0
LV
U2
V2
W2
LV
U2
V2
W2
U3
V3
W3