Setting Notes - Siemens SIPROTEC 7SD610 Manual

2.12.2

Setting Notes

General
Frequency protection is only in effect and accessible if address 136 FREQUENCY Prot. is set to Enabled
during configuration of protection functions. If the function is not required, Disabled is to be set.
The frequency protection function features 4 frequency stages f1 to f4 each of which can function as overfre-
quency stage or underfrequency stage. Each stage can be set active or inactive. This is set in addresses:
• 3601 O/U FREQ. f1 for frequency stage f1,
• 3611 O/U FREQ. f2 for frequency stage f2,
• 3621 O/U FREQ. f3 for frequency stage f3,
• 3631 O/U FREQ. f4 for frequency stage f4,
The following 3 options are available:
• Stage OFF: The stage is ineffective;
• Stage ON: with Trip: The stage is effective and issues an alarm and a trip command (after time has
expired) following irregular frequency deviations;
• Stage ON: Alarm only: The stage is effective and issues an alarm but no trip command following irregular
frequency deviations.
Pickup values, delay time
The configured pickup value determines whether a frequency stage is to respond to overfrequency or under-
frequency.
• If a stage is set to a value above the rated frequency, it is automatically interpreted to be an overfrequency
stage f>.
• If a stage is set to a value below the rated frequency, it is automatically interpreted to be an underfrequency
stage f<.
• If a stage is set exactly to the rated frequency, it is inactive.
A pickup value can be set for each stage according to above rules. The addresses and possible setting ranges
are determined by the nominal frequency as configured in the Power System Data 1 (Section 2.1.2.1) in Rated
Frequency (address 230).
Please note that none of the frequency stages is set to less than 30 mHz above (for f>) or below (for f<) the
nominal frequency. Since the frequency stages have a hysteresis of approx. 20°mHz, it may otherwise happen
that the stage does not drop out when returning to the nominal frequency.
Only those addresses are accessible that match the configured nominal frequency. For each element, a trip
delay time can be set:
• Address 3602 f1 PICKUP pickup value for frequency stage f1 at f
Address 3603 f1 PICKUP pickup value for frequency stage f1 at f
Address 3604 T f1 trip delay for frequency stage f1;
• Address 3612 f2 PICKUP pickup value for frequency stage f2 at f
Address 3613 f2 PICKUP pickup value for frequency stage f2 at f
Address 3614 T f2 trip delay for frequency element f2;
• Address 3622 f3 PICKUP pickup value for frequency stage f3 at f
Address 3623 f3 PICKUP pickup value for frequency stage f3 at f
Address 3624 T f3 trip delay for frequency stage f3;
• Address 3632 f4 PICKUP pickup value for frequency stage f4 at f
Address 3633 f4 PICKUP pickup value for frequency stage f4 at f
Address 3634 T f4 trip delay for frequency element f4.
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
2.12 Frequency Protection (optional)
= 50 Hz,
N
= 60 Hz,
N
= 50 Hz,
N
= 60 Hz,
N
= 50 Hz,
N
= 60 Hz,
N
= 50 Hz,
N
= 60 Hz,
N
Functions
175