Functions
2.11 Undervoltage and Overvoltage Protection (optional)
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
167
If the voltage transformers are located on the line side, the measuring voltages will be missing when the line is
disconnected. To avoid that the undervoltage levels in these cases are or remain picked up, the current criterion
CURR.SUP.Uphph<
(address
3768
) is switched
ON
. With busbar side voltage transformers it can be switched
OFF
. However, if the busbar is dead, the undervoltage protection will pick up and expire and then remain in a
picked-up state. It must therefore be ensured in such cases that the protection is blocked by a binary input.
Undervoltage positive sequence system U
1
The positive sequence undervoltage stages can be used instead of or in addition to previously mentioned un-
dervoltage stages. Depending on your choice, set address
3771
U1<(<)
to
ON
,
OFF
,
Alarm Only
or
U<Alarm U<<Trip
.
Basically, the same considerations apply as for the other undervoltage stages. Especially in case of stability
problems, the positive sequence system is advantageous, since the positive sequence system is relevant for
the limit of the stable energy transmission.
To achieve the two-stage condition, the
U1<
stage (address
3772
) is combined with a greater time delay
T U1<
(address
3773
), and the
U1<<
stage (address
3774
) with a shorter time delay
T U1<<
(address
3775
).
Note that the positive sequence system is calculated according to its defining equation
U
1
=
1
/
3
·|U
L1
+ a·U
L2
+ a
2
·U
L3
|. For symmetrical voltages this is equivalent to a phase-to-earth voltage.
The dropout to pickup ratio
U1<(<) RESET
can be set in address
3779
. This parameter can only be altered
in DIGSI at
Display Additional Settings
.
If the voltage transformers are located on the line side, the measuring voltages will be missing when the line is
disconnected. To avoid that the undervoltage levels in these cases are or remain picked up, the current criterion
CURR.SUP.U1<
(address
3778
) is switched
ON
. With busbar side voltage transformers it can be switched
OFF
.
However, if the busbar is dead, the undervoltage protection will pick up and expire and then remain in a picked-
up state. It must therefore be ensured in such cases that the protection is blocked by a binary input.
2.11.4
Settings
Addresses which have an appended "A" can only be changed with DIGSI, under Additional Settings.
Addr.
Parameter
Setting Options
Default Setting
Comments
3701
Uph-e>(>)
OFF
Alarm Only
ON
U>Alarm U>>Trip
OFF
Operating mode Uph-e overvolt-
age prot.
3702
Uph-e>
1.0 .. 170.0 V;
∞
85.0 V
Uph-e> Pickup
3703
T Uph-e>
0.00 .. 100.00 sec;
∞
2.00 sec
T Uph-e> Time Delay
3704
Uph-e>>
1.0 .. 170.0 V;
∞
100.0 V
Uph-e>> Pickup
3705
T Uph-e>>
0.00 .. 100.00 sec;
∞
1.00 sec
T Uph-e>> Time Delay
3709A
Uph-e>(>) RESET
0.30 .. 0.99
0.98
Uph-e>(>) Reset ratio
3711
Uph-ph>(>)
OFF
Alarm Only
ON
U>Alarm U>>Trip
OFF
Operating mode Uph-ph overvolt-
age prot.
3712
Uph-ph>
2.0 .. 220.0 V;
∞
150.0 V
Uph-ph> Pickup
3713
T Uph-ph>
0.00 .. 100.00 sec;
∞
2.00 sec
T Uph-ph> Time Delay
3714
Uph-ph>>
2.0 .. 220.0 V;
∞
175.0 V
Uph-ph>> Pickup
Содержание SIPROTEC 7SD610
Страница 16: ...Contents SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 16 ...
Страница 267: ...Functions 2 18 Command Processing SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 267 ...
Страница 268: ...Functions 2 18 Command Processing SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 268 ...
Страница 428: ...Appendix A 10 Measured Values SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 428 ...
Страница 430: ...Literature SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 430 ...
Страница 442: ...Glossary SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 442 ...
Страница 448: ...Index SIPROTEC 7SD610 Manual C53000 G1176 C145 6 Release date 02 2011 448 ...