GE D90 Plus - Page 654

644 D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
PHASE DISTANCE APPLIED TO POWER TRANSFORMERS CHAPTER 15: THEORY OF OPERATION
Table 25: Phase distance input signals for wye-delta transformers
Dy5 AB
BC
CA
Dy7 AB
BC
CA
Dy9 AB
BC
CA
Dy11 AB
BC
CA
Transformer
connection
Loop Current transformation Voltage transformation
Yd1 AB
BC
CA
Yd3 AB
BC
CA
Transformer
connection
Loop Current transformation Voltage transformation
BAB
II 3_21P -=
()
AB
BC
AB
VVV -=
3
1
_21P
CBC
II 3_21P -=
()
BC
CA
BC
VVV -=
3
1
_21P
ACA
II 3_21P -=
()
CA
AB
CA
VVV -=
3
1
_21P
AAB
II 3_21P -=
()
AB
CA
AB
VVV -=
3
1
_21P
B
BC
II 3_21P -=
()
BC
AB
BC
VVV -=
3
1
_21P
C
CA
II 3_21P -=
()
CA
BC
CA
VVV -=
3
1
_21P
CAB
II 3_21P -=
()
BC
CA
AB
VVV -=
3
1
_21P
ABC
II 3_21P -=
()
CA
ABBC
VVV -=
3
1
_21P
BCA
II 3_21P -=
()
AB
BCCA
VVV -=
3
1
_21P
BAB
II 3_21P -=
()
BC
AB
AB
VVV -=
3
1
_21P
CBC
II 3_21P -=
()
CA
BC
BC
VVV -=
3
1
_21P
ACA
II 3_21P -=
()
AB
CA
CA
VVV -=
3
1
_21P
()
CBAAB
IIII --= 2
3
1
_21P
AAB
VV 3_21P =
()
CABBC
IIII --= 2
3
1
_21P
BBC
VV 3_21P =
()
BACCA
IIII --= 2
3
1
_21P
CCA
VV 3_21P =
()
CBAAB
IIII 2
3
1
_21P -+=
CAB
VV 3_21P -=
()
ACBBC
IIII 2
3
1
_21P -+=
A
BC
VV 3_21P -=
()
BCACA
IIII 2
3
1
_21P -+=
B
CA
VV 3_21P -=