Woodward HighPROTEC - Page 828

Protective Elements
Convert all data to generator base
Base 1:
• Base power = S
N
• Base voltage V
N
• Base impedance X
N
Base 2:
• Base power = S
B
• Base voltage V
B
• Base impedance X
B
[1.] From this it follows:
X
B
= X
N
⋅
S
B
S
N
⋅(
V
N
V
B
)
2
[2.] Convert unit transformer impedance X
T
to generator-based impedance X
TG
using [1.]:
X
TG
= X
T
⋅
S
G
S
T
⋅(
V
TL
V
G
)
2
=0.11607( pu)
[3.] Convert system impedance Z
max,S1
to transformer-based impedance Z
max,ST1
:
Z
max, ST1
=Z
max , S1
⋅
S
T
S
S
⋅(
V
S
V
TH
)
2
=0.001967+ j0.038623( pu)
[4.] Convert transformer-based system impedance Z
max,ST1
to generator-based impedance Z
max,SG1
:
Z
max, SG1
=Z
max ,ST1
⋅
S
G
S
T
⋅(
V
TL
V
G
)
2
=0.002055+ j0.040352( pu)
[5.] Convert the positive sequence system impedance at minimum generation Z
min,S1
to generator based
impedance Z
min,SG1
in the same way as [3.] and [4.]:
Z
min ,SG1
=0.00422+ j0.06621 ( pu)
[6.] Convert the positive sequence impedance of the longest transmission line Z
LL1
to generator-based impedance
Z
LLG1
in the same way as [3.] and [4.]:
Z
LLG1
=0.04404+ j0.46437 ( pu)
[7.] Convert the positive sequence impedance of the shortest transmission line Z
SL1
to generator-based impedance
Z
SLG1
in the same way as [3.] and [4.]:
Z
SLG1
=0.02196+ j0.23219( pu)
Single-line diagram with generator-based data.
828 MCDGV4 DOK-HB-MCDGV4-2E