Functionality - ABB REG670 Technical Manual

1MRK502052-UEN B
10.2.2
10.2.3
10.2.4
Technical manual

Functionality

Overfrequency protection function SAPTOF is applicable in all situations, where
reliable detection of high fundamental power system frequency is needed.
Overfrequency occurs because of sudden load drops or shunt faults in the power
network. Close to the generating plant, generator governor problems can also cause
over frequency.
SAPTOF measures frequency with high accuracy, and is used mainly for generation
shedding and remedial action schemes. It is also used as a frequency stage initiating
load restoring. A definite time delay is provided for operate.
SAPTOF 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
Function block
SAPTOF
U3P* TRIP
BLOCK START
BLKTRIP BLKDMAGN
FREQ
IEC06000280_2_en.vsd
IEC06000280 V2 EN
Figure 265: SAPTOF function block
Signals
Table 309: SAPTOF Input signals
Name Type
U3P GROUP
SIGNAL
BLOCK BOOLEAN
BLKTRIP BOOLEAN
Table 310: SAPTOF Output signals
Name Type
TRIP BOOLEAN
START BOOLEAN
BLKDMAGN BOOLEAN
FREQ REAL
Frequency protection
Default Description
- Three phase group signal for voltage inputs
0 Block of function
0 Blocking operate output
Description
General trip signal
General start signal
Measurement blocked due to low amplitude
Measured frequency
Section 10
549