ABB RELION 670 Series Technical Manual page 603

1MRK 502 066-UUS B
Simplified logic diagram for lockout functionality is shown in Figure321.
AutoLockout
TRIP
SETLKOUT
RESET
BLOCK
IEC12000020 V2 EN-US
Figure 321: Trip Lockout logic
Alarm ripple detection
The rotor winding is provided with DC excitation current through the rectifier bridge and the
excitation transformer. In case a fault happens in the rectifier circuit, for example a short circuit or
broken diode/thyristor, the rotor system is endangered, due to asymmetry in the three phase
currents. This asymmetry will cause a ripple in the rotor DC current. This alarm method estimates
the ripple of the rotor DC current and if it exceed the preset level (parameter
start a timer (defined by parameter
will be given.
The service value for the ripple level is provided. It is recommended to check the natural ripple of
the rotor DC current at site before the level for parameter
ripple supervision shall only be used if the rotor DC current is used as measured quantity.
8.18.8 Technical data
Table 332: GRPTTR (49R) technical data
Function
Overcurrent start level for
overload protection
Reset ratio, overcurrent
Start time, overcurrent at 0 to
2 x I
set
Thermal time characteristic
Minimum operate time for
thermal characteristic
Maximum operate time for
thermal characteristic
Undercurrent start level
Table continues on next page
Technical manual
AND
OR
tAlarmRipple ). Once this timer has expired the signal ALRIPPLE
Range or value
(105.0–900.0)% of IBase
>95%
Min = 50 ms
Max = 170 ms
According to
IEEE Std C50.13–2005
(1.0–120.0) s
(100.0–2000.0) s
(5.0–500.0)% of IBase
LOCKOUT
AND
AND
IEC12000020-2-en.vsdx
AlmRippleLev is set. Note that this
Accuracy
±1.0% of I at I ≤ I
r
±1.0% of I at I > I
—
—
±1.5% or ±200 ms whichever is greater
±1.5% or ±200 ms whichever is greater
±1.5% or ±200 ms whichever is greater
±1.0% of I at I ≤ I
r
±1.0% of I at I > I
Section 8
Current protection
AlmRippleLev ) it will
GUID-98497E6C-7570-4160-926B-AEA3A24C42B6 v1
GUID-A1CB5B4F-768E-4B1B-937E-B91EC3EFA2CC v3
r
r
r
r
597