Identification; Functionality; Function Block; Signals - ABB RET650 Technical Manual

1MRK 504 135-UEN A
10.2.1
10.2.2
10.2.3
10.2.4
Technical manual

Identification

Function description
Overfrequency protection

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.

Function block

SAPTOF
U3P* TRIP
BLOCK START
BLKDMAGN
IEC09000280_1_en.vsd
IEC09000280 V1 EN
Figure 105: SAPTOF function block

Signals

Table 159: SAPTOF Input signals
Name Type
U3P GROUP
SIGNAL
BLOCK BOOLEAN
Frequency protection
IEC 61850 IEC 60617
identification identification
SAPTOF
SYMBOL-O V1 EN
Default Description
- Three phase group signal for voltage inputs
0 Block of function
Section 10
ANSI/IEEE C37.2
device number
81
f >
235