Setting Parameters - ABB RET670 Applications Manual

Section 3
IED application
3.9.1.3
Table 139: SAPTUF (81) Group settings (basic)
Name Values (Range)
Operation Disabled
Enabled
Vbase 0.05 - 2000.00
PUFrequency 35.00 - 75.00
IntBlockLevel 0 - 100
TimeDlyOperate 0.000 - 60.000
TimeDlyReset 0.000 - 60.000
TimeDlyRestore 0.000 - 60.000
RestoreFreq 45.00 - 65.00
TimerOperation Definite timer
Volt based timer
VNom 50 - 150
VMin 50 - 150
Exponent 0.0 - 5.0
t_MaxTripDelay 0.010 - 60.000
t_MinTripDelay 0.010 - 60.000
544
Power system protection, by load shedding
The setting has to be well below the lowest occurring "normal" frequency and well
above the lowest acceptable frequency for power stations, or sensitive loads. The
setting level, the number of levels and the distance between two levels (in time and/or
in frequency) depends very much on the characteristics of the power system under
consideration. The size of the "largest loss of production" compared to "the size of the
power system" is a critical parameter. In large systems, the load shedding can be set at
a fairly high frequency level, and the time delay is normally not critical. In smaller
systems the frequency pickup level has to be set at a lower value, and the time delay
must be rather short.
The voltage related time delay is used for load shedding. The settings of the
underfrequency function could be the same all over the power system. The load
shedding is then performed firstly in areas with low voltage magnitude, which
normally are the most problematic areas, where the load shedding also is most efficient.

Setting parameters

Unit Step
- -
kV 0.05
Hz 0.01
%VB 1
s 0.001
s 0.001
s 0.001
Hz 0.01
- -
%VB 1
%VB 1
- 0.1
s 0.001
s 0.001
Default Description
Disabled Disable/Enable Operation
400.00 Base voltage
48.80 Frequency setting pickup value.
50 Internal blocking level in % of VBase.
0.200 Operate time delay in over/under-frequency
mode.
0.000 Time delay for reset.
0.000 Restore time delay.
50.10 Restore frequency if frequency is above
frequency value.
Definite timer Setting for choosing timer mode.
100 Nominal voltage in % of VBase for voltage
based timer.
90 Lower operation limit in % of VBase for
voltage based timer.
1.0 For calculation of the curve form for voltage
based timer.
1.000 Maximum time operation limit for voltage
based timer.
1.000 Minimum time operation limit for voltage
based timer.
1MRK504116-UUS C
Application manual