Functions
6-131
7SA6 Manual
C53000-G1176-C156-2
Figure 6-75
Setting parameter characteristics in the logarithmic–inverse curve
Zero Sequence
Voltage Stage with
Inverse
Characteristic
For the zero sequence voltage controlled stage (address
131
Earth Fault O/C
=
U0 inverse
) the operating mode is initially set: address
3140
Op. mode 3I0p
. This
stage can be set to operate
Forward
(usually towards line) or
Reverse
(usually to-
wards busbar) or
Non-Directional
(in both directions). If this stage is not required,
set its mode to
Inactive
.
Address
3141
3I0p PICKUP
indicates the minimum current value above which this
stage is required to operate. The value must be exceeded by the minimum earth fault
current value.
The voltage-controlled characteristic is based on the following formula:
U
0
is the actual zero sequence voltage. U
0 min
is the setting value
U0inv. minimum
(Address
3183
). Please take into consideration that the formulae is based on the zero
sequence voltage U
0
, not on 3U
0
. The function is illustrated in the Technical Data Sec-
tion (10.5, Figure 10-5).
Figure 6-76 shows the most important parameters.
U0inv. minimum
displaces the
voltage-controlled characteristic in direction of 3U
0
. The set value is the asymptote for
this characteristic (t
→ ∞
). In Figure 6-76 a' shows an asymptote that belongs to the
characteristic a.
The minimum voltage
3U0>(U0 inv)
(address
3182
) is the lower voltage threshold.
It corresponds to the line c in Figure 6-76. In characteristic b the curve is cut by the
minimum voltage
3U0>(U0 inv)
(line c).
An additional time
T forw. (U0inv)
(address
3184
) that is added to the voltage-
controlled characteristic can be set for directional-controlled tripping. The directional
additional time is usually not required and set to 0.
With the non-directional time
T rev. (U0inv)
(Address
3185
) a non-directional
back-up stage can be generated.
0
1
3I0p MaxT-DELAY
3
I
0
/
3I0p PICKUP
3I0p Time Dial
3I0p MinT-DELAY
3I0p Startpoint
t
t
2 s
0,25 U
0
V
⁄
U
0 min
V
⁄
–
-----------------------------------------------------------
=
Содержание siprotec 7SA6
Страница 2: ...Siemens Aktiengesellschaft Book No C53000 G1176 C156 2 ...
Страница 18: ...xviii 7SA6 Manual C53000 G1176 C156 2 ...
Страница 32: ...Introduction 1 14 7SA6 Manual C53000 G1176 C156 2 ...
Страница 82: ...Hardware and Connections 2 50 7SA6 Manual C53000 G1176 C156 2 ...
Страница 119: ...SIPROTEC 4 Devices 4 25 7SA6 Manual C53000 G1176 C156 2 Figure 4 20 CFC Logic example ...
Страница 190: ...Configuration 5 62 7SA6 Manual C53000 G1176 C156 2 ...
Страница 559: ...Control During Operation 7 45 7SA6 Manual C53000 G1176 C156 2 Figure 7 45 Circuit breaker trip test in DIGSI 4 ...
Страница 652: ...Installation and Commissioning 8 78 7SA6 Manual C53000 G1176 C156 2 ...
Страница 724: ...Technical Data 10 56 7SA6 Manual C53000 G1176 C156 ...
Страница 800: ...Appendix A 76 7SA6 Manual C53000 G1176 C156 2 ...
Страница 866: ...Appendix B 66 7SA6 Manual C53000 G1176 C156 2 ...