Siemens SIPROTEC 7SD610 User Manual

Functions
2.12 Frequency Protection (optional)
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
176
The set times are additional delay times not including the operating times (measuring time, dropout time) of the
protection function.
If underfrequency protection is used for load shedding purposes, then the frequency settings relative to other
feeder relays are generally based on the priority of the customers served by the protection relay. Normally, it is
required for load shedding a frecuency / time grading that takes into account the importance of the consumers
or consumer groups.
In interconnected networks, frequency deviations may also be caused by power swings. Depending on the
power swing frequency, the mounting location of the device and the setting of the frequency stages, it is rea-
sonable to block the entire frequency protection function or single stages once a power swing has been detect-
ed. The delay times must then be co-ordinated thus that a power swing is detected before the frequency pro-
tection trips.
Further application examples exist in the field of power stations. The frequency values to be set mainly depend,
also in these cases, on the specifications of the power system/power station operator. In this context, the un-
derfrequency protection also ensures the power station’s own demand by disconnecting it from the power
system on time. The turbo regulator regulates the machine set to the nominal speed. Consequently, the sta-
tion's own demands can be continuously supplied at nominal frequency.
Since the dropout threshold is 20 mHz below or above the trip frequency, the resulting „minimum“ trip frequency
is 30 mHz above or below the nominal frequency.
A frequency increase can, for example, occur due to a load shedding or malfunction of the speed regulation
(e.g. in a stand-alone system). In this way, the frequency protection can, for example, be used as overspeed
protection.
2.12.3 Settings
Addr. Parameter Setting Options Default Setting Comments
3601 O/U FREQ. f1 ON: Alarm only
ON: with Trip
OFF
ON: Alarm only Over/Under Frequency Protection
stage f1
3602 f1 PICKUP 45.50 .. 54.50 Hz 49.50 Hz f1 Pickup
3603 f1 PICKUP 55.50 .. 64.50 Hz 59.50 Hz f1 Pickup
3604 T f1 0.00 .. 600.00 sec 60.00 sec T f1 Time Delay
3611 O/U FREQ. f2 ON: Alarm only
ON: with Trip
OFF
ON: Alarm only Over/Under Frequency Protection
stage f2
3612 f2 PICKUP 45.50 .. 54.50 Hz 49.00 Hz f2 Pickup
3613 f2 PICKUP 55.50 .. 64.50 Hz 57.00 Hz f2 Pickup
3614 T f2 0.00 .. 600.00 sec 30.00 sec T f2 Time Delay
3621 O/U FREQ. f3 ON: Alarm only
ON: with Trip
OFF
ON: Alarm only Over/Under Frequency Protection
stage f3
3622 f3 PICKUP 45.50 .. 54.50 Hz 47.50 Hz f3 Pickup
3623 f3 PICKUP 55.50 .. 64.50 Hz 59.50 Hz f3 Pickup
3624 T f3 0.00 .. 600.00 sec 3.00 sec T f3 Time Delay
3631 O/U FREQ. f4 ON: Alarm only
ON: with Trip
OFF
ON: Alarm only Over/Under Frequency Protection
stage f4

Siemens SIPROTEC 7SD610 Specifications

General

Brand	Siemens
Model	SIPROTEC 7SD610
Category	Relays
Language	English