ABB RELION 650 Series Applications Manual page 80

Section 6
Differential protection
5. Enter the following settings for all three CT input channels used for the HV side CTs, see
table 11.
Table 11:
Setting parameter
CTprim
CTsec
CTStarPoint
To compensate for delta connected CTs, see equation 15.
6. Assume GBASVAL:1 is used for winding 1 (W1, HV-side) base values: Set Ibase = 175 A (rated
current), Ubase= 69 kV (rated voltage).
7. Assume GBASVAL:2 is used for winding 2 (W2, LV-side) base values: Set Ibase = 965 A (rated
current), Ubase= 12.5 kV (rated voltage).
8. Enter the following values for the general settings of the Transformer differential protection
function, see table 12.
Table 12:
Setting parameter
GlobalBaseSelW1
GlobalBaseSelW2
ConnectTypeW1
ConnectTypeW2
ClockNumberW2
ZSCurrSubtrW1
ZSCurrSubtrW2
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-star connected power transformer without tap changer
Single line diagrams for two possible solutions for such type of power transformer with all
relevant application data are given in figure 30.
74
CT input channels used for the HV side CTs
Selected value for solution 1
(star connected CT)
300
5
From Object
General settings of the differential protection function
Select value for solution 1 (star
connected CT)
1 (GBASVAL:1)
2 (GBASVAL:2)
STAR (Y)
delta=d
1 [30 deg lag]
On
Off
No
No
Not used
Not relevant for this
application. Use default value.
1MRK 504 158-UEN A
Selected value for solution 2 (delta
connected CT)
300
=
173
3
EQUATION1888 V1 EN-US
5
ToObject
Selected value for solution 2 (delta
connected CT)
1 (GBASVAL:1)
2 (GBASVAL:2)
STAR (Y)
1)
star=y
1)
0 [0 deg]
2)
Off
Off
No
No
Not used
Not relevant for this application. Use
default value.
Application manual
(Equation 15)
SEMOD167854-209 v5