Overfrequency Protection Saptof (81) - ABB RES670 Technical Manual

Section 10
Frequency protection
10.2
10.2.1
10.2.2
308
Function
Reset time, definite time function at f
f + 0.02 Hz
set
Voltage dependent time delay
Exponent
-
é ù
V VMin
(
= ×
t t MaxTripDelay t MinTripDelay _
ê ú
ë - û
VNom VMin
EQUATION1559 V1 EN-US
V=V
measured

Overfrequency protection SAPTOF (81)

Identification
Function description
Overfrequency protection
Functionality
Overfrequency protection function (SAPTOF (81)) 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 (81) 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 trip.
Range or value
- 0.02 Hz to (0.000-60.000)s
set
Settings:
VNom=(50-150)% of V
VMin=(50-150)% of V
Exponent=0.0-5.0
t_MaxTripDelay=(0.010–
60.000)s
t_MinTripDelay=(0.010–
60.000)s
)
- +
_ t MinTripDelay _
IEC 61850 IEC 60617
identification identification
SAPTOF
SYMBOL-O V1 EN-US
Phasor measurement unit RES670 2.2 ANSI
1MRK 511 408-UUS A
Accuracy
±0.2% or ±120
ms whichever is
greater
±1.0% or ±100
ms whichever is
base
greater
base
(Equation 62)
ANSI/IEEE C37.2
device number
81
f >
Technical manual
IP15747-1 v3
M14866-1 v4
M14953-3 v12