ABB Relion 650 Series Technical Manual page 266

Section 8
Frequency protection
8.2.5 Settings
Table 195: SAPTOF (81) Group settings (basic)
Name Values (Range)
Operation Disabled
Enabled
PUFrequency 35.00 - 75.00
tDelay 0.000 - 60.000
8.2.6 Monitored data
Table 196: SAPTOF (81) Monitored data
Name
FREQ
8.2.7 Operation principle
Overfrequency protection SAPTOF (81) is used to detect high power system frequency. SAPTOF
(81) has a settable definite time delay. If the frequency remains above the set value for a time
period corresponding to the chosen time delay, the corresponding TRIP signal is issued. To avoid
an unwanted TRIP due to uncertain frequency measurement at low voltage magnitude, a voltage
controlled blocking of the function is available from the preprocessing function, that is, if the
voltage is lower than the set blocking voltage in the preprocessing function, the function is
blocked and no PICKUP or TRIP signal is issued.
8.2.7.1 Measurement principle
The fundamental frequency of the positive sequence voltage is measured continuously, and
compared with the set value,
on the voltage magnitude. If the voltage magnitude decreases below the setting
in the SMAI preprocessing function, which is set as a percentage of a global base voltage
parameter
settings are made in percent of the global parameter
PICKUP signal, a hysteresis has been included.
8.2.7.2 Time delay
The time delay for SAPTOF (81) is a settable definite time delay, specified by the setting
TRIP signal issuing requires that the over frequency condition continues for at least the user set
time delay. If the PICKUP condition, with respect to the measured frequency ceases during the
delay time, and is not fulfilled again within a defined reset time, the PICKUP output is reset.
260
Unit Step
-
Hz
s
Type Values (Range)
REAL -
PUFrequency . Over frequency protection SAPTOF (81) is dependent
VBase , SAPTOF (81) is blocked, and the output BLKDMAGN is issued. All voltage
© Copyright 2011 ABB Power Grids. All rights reserved
Default
- Disabled
0.01 51.20
0.001 0.200
Unit
Hz
VBase . To avoid oscillations of the output
1MRK 506 326-UUS B
Description
Operation Disable / Enable
Frequency set value
Operate time delay
Description
Measured frequency
MinValFreqMeas
Line distance protection REL650
Technical manual
PID-1968-SETTINGS v6
PID-1968-MONITOREDDATA v8
M14958-3 v4
M14958-6 v5
M14958-9 v4
tDelay .