ABB 615 Series - Page 480

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 I
AmLV
A C
−
− −
=
−
3
GUID-40A4A54A-160D-4745-A2D3-A81C5BFC8C1F V1 EN (Equation 73)
I
I I
BmLV
B A
−
− −
=
−
3
GUID-041FD5D6-FE2B-487E-8BF4-AC44FD0C4D34 V1 EN (Equation 74)
I
I I
CmLV
C B
−
− −
=
−
3
GUID-BD2F98BD-4BB1-4F8B-AD4E-0EEA8BADBAF3 V1 EN (Equation 75)
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
transformer
Winding 1 type Winding 2 type Phase shift Zero sequence
current elimination
Yy0 Y y 0 Not needed
YNy0 YN y 0 HV side
YNyn0 YN yn 0 HV & LV side
Yyn0 Y yn 0 LV side
Yy2 Y y 2 Not needed
YNy2 YN y 2 (Automatic)
YNyn2 YN yn 2 (Automatic)
Yyn2 Y yn 2 (Automatic)
Yy4 Y y 4 Not needed
YNy4 YN y 4 (Automatic)
YNyn4 YN yn 4 (Automatic)
Yyn4 Y yn 4 (Automatic)
Yy6 Y y 6 Not needed
YNy6 YN y 6 HV side
YNyn6 YN yn 6 HV & LV side
Table continues on next page
Section 4 1MAC059074-MB A
Protection functions
474 615 series ANSI
Technical Manual