10.3.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Rate-of-change frequency protection SAPFRC
SYMBOL-N V1 EN
81
10.3.2 Functionality
The rate-of-change frequency protection function SAPFRC gives an early indication
of a main disturbance in the system. SAPFRC measures frequency with high
accuracy, and can be used for generation shedding, load shedding and remedial action
schemes. SAPFRC can discriminate between a positive or negative change of
frequency. A definite time delay is provided for operate.
SAPFRC is provided with an undervoltage blocking.
10.3.3 Function block
SAPFRC
U3P*
BLOCK
TRIP
START
RESTORE
BLKDMAGN
IEC09000281_1_en.vsd
IEC09000281 V1 EN
Figure 154: SAPFRC function block
10.3.4 Signals
Table 194: SAPFRC Input signals
Name
Type Default Description
U3P GROUP
SIGNAL
- Three phase group signal for voltage inputs
BLOCK BOOLEAN 0 Block of function
Table 195: 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
1MRK 502 048-UEN A Section 10
Frequency protection
303
Technical manual