ABB REG670 - Settings

Table 316: SAPFRC Output signals
Name Type Description
TRIP BOOLEAN Operate/trip signal for frequency gradient
START BOOLEAN Start/pick-up signal for frequency gradient
RESTORE BOOLEAN Restore signal for load restoring purposes
BLKDMAGN BOOLEAN Blocking indication due to low amplitude
10.3.5 Settings
Table 317: SAPFRC Group settings (basic)
Name Values (Range) Unit Step Default Description
Operation Off
On
- - Off Operation Off / On
StartFreqGrad -10.00 - 10.00 Hz/s 0.01 0.50 Frequency gradient start value, the sign
defines direction
tTrip 0.000 - 60.000 s 0.001 0.200 Operate time delay in positive / negative
frequency gradient mode
RestoreFreq 45.00 - 65.00 Hz 0.01 49.90 Restore frequency value
tRestore 0.000 - 60.000 s 0.001 0.000 Restore time delay
tReset 0.000 - 60.000 s 0.001 0.000 Time delay for reset
10.3.6 Monitored data
Table 318: SAPFRC Monitored data
Name
Type Values (Range) Unit Description
STARTDUR REAL - % Start duration in percents
of the total operation time
10.3.7 Operation principle
Rate-of-change frequency protection SAPFRC is used to detect fast power system
frequency changes at an early stage. SAPFRC has a settable definite time delay. If the
rate-of-change of frequency remains below the set value, for negative rate-of-change,
for a time period equal to the chosen time delay, the TRIP signal is issued. If the rate-
of-change of frequency remains above the set value, for positive rate-of-change, for a
time period equal to the chosen time delay, the TRIP signal is issued. To avoid an
unwanted trip due to uncertain frequency measurement at low voltage magnitude a
voltage controlled blocking of the function is available from the preprocessing
function. If the voltage is lower than the set blocking voltage in the preprocessing
function the function is blocked and no START or TRIP signal is issued. If the
frequency recovers, after a frequency decrease, a restore signal is issued.
Section 10 1MRK502052-UEN B
Frequency protection
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Technical manual