The vector group matching can be implemented either on both, winding 1 and winding 2,
or only on winding 1 or winding 2, at intervals of 30° with the Clock number setting.
When the vector group matching is Yy0 and the CT connection type is according to "Type
2", the phase angle of the phase currents connected to the protection relay does not change.
When the vector group matching is Yy6, the phase currents are turned 180° in the
protection relay.
Example 1
Vector group matching of a Ynd11-connected power transformer on winding 1, CT
connection type according to type 1. The Winding 1 type setting is ”YN”, Winding 2 type
is “d” and Clock number is “Clk Num 11”. This is compensated internally by giving
winding 1 internal compensation value +30° and winding 2 internal compensation value
0°:
I
I I
I
I I
I
I I
AmHV
A B
BmHV
B C
CmHV
C A
=
−
=
−
=
−
3
3
3
GUID-88668B82-9EC4-4FE7-AFE0-71360F72543F V1 EN (Equation 83)
Example 2
But 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
I
I I
I
I I
AmLV
A C
BmLV
B A
CmLV
C B
=
−
=
−
=
−
3
3
3
GUID-06FCDC6B-7FD0-4205-886F-D36A4C2EEB38 V1 EN
(Equation 84)
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, however, the matching
is done differently to have the winding 1 neutral current compensated at the same time.
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 503
Technical Manual
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