2 Functions
158
7SD5 Manual
C53000-G1176-C169-1
In the case of parameterization with secondary quantities, the values derived from the
grading coordination chart must be converted to the secondary side of the current and
voltage transformers. In general:
Accordingly, the reach for any distance zone can be specified as follows:
with
N
CT
= Current transformer ratio
N
VT
= Transformation ratio of voltage transformer
On long, heavily loaded lines, the MHO characteristic may extend into the load imped-
ance range. This is of no consequence as the pickup by overload is prevented by the
load trapezoid. Refer to margin heading „Load Area“ in Section 2.5.1.
Calculation Example:
110 kV overhead line 150 mm
2
with the following data:
s (length)
= 35 km
R
1
/s =
0.19
Ω
/km
X
1
/s =
0.42
Ω
/km
R
0
/s =
0.53
Ω
/km
X
0
/s =
1.19
Ω
/km
Current Transformer 600 A / 5 A
Voltage Transformer 110 kV / 0.1 kV
The following line data is calculated:
R
L
= 0.19
Ω
/km · 35 km = 6.65
Ω
X
L
= 0.42
Ω
/km · 35 km = 14.70
Ω
For the first zone, a setting of 85 % of the line length should be applied, which results
in primary:
X1
prim
= 0.85 · X
L
= 0.85 · 14.70
Ω
= 12.49
Ω
or secondary:
Independent Zones
Z1 up to Z5
Each zone can be set using the parameter MODE
Forward
or
Reverse
(address
1701
Op. mode Z1
,
1711
Op. mode Z2
,
1721
Op. mode Z3
,
1731
Op. mode
Z4
and
1741
Op. mode Z5
). This allows any combination of forward or reverse
graded zones. Zones that are not required, are set
Inactive
.
The values derived from the grading coordination chart are set for each of the required
zones. The setting parameters are grouped for each zone. For the first zone these are
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Страница 2: ...2 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 4: ...4 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 18: ...Contents 18 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 34: ...1 Introduction 34 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 444: ...2 Functions 444 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 580: ...4 Technical Data 580 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 682: ...Literature 682 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 698: ...Index 698 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...