ABB REG670 Technical Manual page 125

1MRK502052-UEN B
Technical manual
Matrix for winding with 120°
leading
Matrix for winding with 90°
leading
Matrix for winding with 60°
leading
Matrix for winding with 30°
leading
By using this table complete equation for calculation of fundamental frequency
differential currents for two winding power transformer with YNd5 vector group and
enabled zero sequence current reduction on HV side will be derived. From the given
power transformer vector group the following is possible to be concluded:
1. The HV star (Y) connected winding will be used as the reference winding and
zero sequence currents shall be subtracted on that side
2. The LV winding is lagging for 150°
With the help of table 47, the following matrix equation can be written for this power
transformer:
- -
é IDL 1 ù é 2 1
1
ê ú ê
= × - - ×
IDL 2 1 2
ê ú ê
3
ê ú ê - -
IDL 3 1 1 2
ë û ë
EQUATION2015 V1 EN
where:
IDL1 is the fundamental frequency differential current in phase L1 (in W1 side primary amperes)
IDL2 is the fundamental frequency differential current in phase L2 (in W1 side primary amperes)
IDL3 is the fundamental frequency differential current in phase L3 (in W1 side primary amperes)
Table continues on next page
Matrix with Zero Sequence
Reduction set to On
é - - ù
1 2 1
1 ê ú
× - -
1 1 2
ê ú
3
ê ú
- -
ë 2 1 1 û
(Equation 15)
EQUATION1239 V1 EN
é ù
0 1 -1
1 ê ú
×
-1 0 1
ê ú
3
ê ú
-
ë 1 1 0 û
(Equation 17)
EQUATION1241 V1 EN
é - ù
1 1 2
1
ê ú
× -
2 1 1
ê ú
3
ê ú
-
1 2 1
ë û
(Equation 18)
EQUATION1242 V1 EN
é ù
1 0 -1
1 ê ú
×
-1 1 0
ê ú
3
ê ú
-
ë 0 1 1 û
(Equation 20)
EQUATION1244 V1 EN
1 ù é IL W 1_ 1 ù
Ur W _ 2 1
ú ê ú
+
1 IL 2 _ 1 W
ú ê ú
Ur W _ 1
ú ê ú
IL 3_ 1 W
û ë û
Section 6
Differential protection
Matrix with Zero Sequence
Reduction set to Off
é ù
0 1 0
ê ú
0 0 1
ê ú
ê ú
ë 1 0 0 û
EQUATION1240 V1 EN
Not applicable. Matrix on the
left used.
é - ù
0 0 1
ê ú
-
1 0 0
ê ú
ê ú
-
ë 0 1 0 û
EQUATION1243 V1 EN
Not applicable. Matrix on the
left used.
-
é 1 0 1 ù é IL W 1_ 2
ê ú ê
× × - ×
1 1 0 IL 2 _ 2
ê ú ê
3
ê - ú ê
0 1 1 IL 3_ 2
ë û ë
(Equation 16)
(Equation 19)
ù
ú
W
ú
ú
W
û
(Equation 21)
119