ABB Relion REG670, Technical Manual

Page: 559 / 1298

10.3 Rate-of-change frequency protection SAPFRC
10.3.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Rate-of-change frequency protection SAPFRC
df/dt
><
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. The operation is based on
positive sequence voltage measurement and requires two phase-phase or three phase-
neutral voltages to be connected. For information about how to connect analog inputs,
refer to
Application manual/IED application/Analog inputs/Setting guidelines .
10.3.3 Function block
IEC06000281-2-en.vsd
SAPFRC
U3P*
BLOCK
BLKTRIP
BLKREST TRIP
START
RESTORE
BLKDMAGN
IEC06000281 V2 EN
Figure 267: SAPFRC function block
10.3.4 Signals
Table 315: SAPFRC Input signals
Name Type Default Description
U3P GROUP
SIGNAL
- Three phase group signal for voltage inputs
BLOCK BOOLEAN 0 Block of function
BLKTRIP BOOLEAN 0 Blocking operate output
BLKREST BOOLEAN 0 Blocking restore output
1MRK502052-UEN B
Section 10
Frequency protection
553
Technical manual