ABB 615 series Technical Manual page 480

Section 4
Protection functions
474
Example 2, if vector group is Yd11 and CT connection type is according to type 1, the
compensation is a little different. The Winding 1 type setting is "Y", Winding 2 type is "d"
and Clock number is "Clk Num 11". This is compensated internally by giving winding 1
internal compensation value 0° and winding 2 internal compensation value -30°:
− −
I I
−
−
A C
I
=
AmLV
3
GUID-40A4A54A-160D-4745-A2D3-A81C5BFC8C1F V1 EN
− −
I I
−
−
B A
I
=
BmLV
3
GUID-041FD5D6-FE2B-487E-8BF4-AC44FD0C4D34 V1 EN
− −
I I
−
−
C B
I
=
CmLV
3
GUID-BD2F98BD-4BB1-4F8B-AD4E-0EEA8BADBAF3 V1 EN
The "Y" side currents stay untouched, while the "d" side currents are compensated to
match the currents actually flowing in the windings.
In this example there is no neutral current on either side of the transformer (assuming there
are no grounding transformers installed). In the previous example, the matching is done
differently to have the winding 1 neutral current compensated at the same time.
Table 423: 87L vector group matching
Vector group of the Winding 1 type
transformer
Yy0
YNy0
YNyn0
Yyn0
Yy2
YNy2
YNyn2
Yyn2
Yy4
YNy4
YNyn4
Yyn4
Yy6
YNy6
YNyn6
Table continues on next page
Winding 2 type
Y y
YN y
YN yn
Y yn
Y y
YN y
YN yn
Y yn
Y y
YN y
YN yn
Y yn
Y y
YN y
YN yn
1MAC059074-MB A
(Equation 73)
(Equation 74)
(Equation 75)
Phase shift Zero sequence
current elimination
0 Not needed
0 HV side
0 HV & LV side
0 LV side
2 Not needed
2 (Automatic)
2 (Automatic)
2 (Automatic)
4 Not needed
4 (Automatic)
4 (Automatic)
4 (Automatic)
6 Not needed
6 HV side
6 HV & LV side
615 series ANSI
Technical Manual