Siemens siprotec 7SA522 - Oscillographic Fault Records

2 Functions
60
7SA522 Manual
C53000-G1176-C155-3
2.1.6 Oscillographic Fault Records
2.1.6.1 Description
The 7SA522 distance protection is equipped with a fault recording function. The in-
stantaneous values of the measured quantities
i
L1
, i
L2
, i
L3
, i
E
or i
EE
, i
p
, i
y
and u
L1
, u
L2
, u
L3
, u
delta
or u
sync
or u
x
or 3·u
0
(voltages in accordance with connection) are sampled at intervals of 1 ms (for 50 Hz)
and stored in a circulating buffer (20 samples per cycle). For a fault, the data are stored
for an adjustable period of time, but no more than 5 seconds per fault. A total of 8
records can be saved within 15 s. The fault record memory is automatically updated
with every new fault, so no acknowledgment is required. The storage of fault values
can also be started by pickup of a protection function, via binary input and via the serial
interface.
The data can be retrieved via the serial interfaces by means of a personal computer
and evaluated with the protection data processing program DIGSI
®
and the graphic
analysis software SIGRA 4. The latter graphically represents the data recorded during
the system fault and calculates additional information such as the impedance or RMS
values from the measured values. Currents and voltages can be presented as desired
as primary or secondary values. Binary signal traces (marks) of particular events e.g.
“fault detection”, “tripping” are also represented.
If the device has a serial system interface, the fault recording data can be passed on
to a central device via this interface. Data are evaluated by appropriate programs in
the central device. Currents and voltages are referred to their maximum values, scaled
to their rated values and prepared for graphic presentation. Binary signal traces
(marks) of particular events e.g. “fault detection”, “tripping” are also represented.
In the event of transfer to a central device, the request for data transfer can be exe-
cuted automatically and can be selected to take place after each fault detection by the
protection, or only after a trip.
2.1.6.2 Setting Notes
General Other settings pertaining to fault recording (waveform capture) are found in the
submenu Oscillographic Fault Records of the Settings menu. Waveform capture
makes a distinction between the trigger instant for an oscillographic record and the cri-
terion to save the record (address  :$9()25075,**(5). This setting is only pos-
sible via DIGSI
®
at Additional Settings. Normally the trigger is the pickup of a protec-
tive element, i.e. the time 0 is defined as the instant the first protection function picks
up. The criterion for saving may be both the device pickup (6DYHZ3LFNXS) or the
device trip (6DYHZ75,3). A trip command issued by the device can also be used
as trigger instant (6WDUWZ75,3); in this case it is also the saving criterion.
Recording of an oscillographic fault record starts with the pickup by a protective func-
tion and ends with the dropout of the last pickup of a protective function. Usually this
592 1pole open L2 OUT Single pole open detected in L2
593 1pole open L3 OUT Single pole open detected in L3
No. Information Type of In-
formation
Comments