Functions
2.49 Auxiliary Functions
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
344
2.49.10 Oscillographic Fault Records
The multi-functional 7UM62 is equipped with a fault memory which optionally scans either the instantaneous
values or the rms values of various measured quantities for storage in a ring buffer.
2.49.10.1Functional Description
Mode of Operation
The instantaneous values of the measured quantities
i
L1 S1
, i
L2 S1
, i
L3 S1
, i
EE1
, i
L1 S2
, i
L2 S2
, i
L3 S2
, i
EE2
and u
L1
, u
L2
, u
L3
, u
E
, I
diffL1
, I
diffL2
, I
diffL3
, I
stabL1
, I
stabL2
, I
stabL3
(referred
to the nominal object current) and u
=
or i
=
of the three measuring transducers
are sampled at intervals of 1,25 ms (for 50 Hz)and stored in a ring buffer (16 samples per cycle). In the event
of a fault, the data are recorded for a set period of time, but not for more than 5 seconds.
The rms values
of the measured quantities
I
1
, I
2
, I
ee2
, I
ee1
, U
1
, U
E
, P, Q, ϕ, f–f
N
, R and X
can be deposited in a ring buffer, one measured value per cycle. R and X are the positive sequence impedanc-
es. In the event of a fault, the data are recorded for a set period of time, but not for more than 80 seconds.
Up to 8 fault records can be stored in this buffer. The fault record memory is automatically updated with every
new fault, so no acknowledgment is required. The fault record buffer can also be started with protection pickup,
via binary input, operator interface or 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. The latter graphically rep-
resents the data recorded during the system fault and calculates additional information such as impedance or
rms values from the measured values. Currents and voltages can be presented as desired as primary or sec-
ondary values. Binary signal traces (marks) of particular events, e.g. „pickup“, „tripping“ are also represented.
If the device has a serial system interface, the fault recording data can be passed on to a central device (e.g.
SICAM) via this interface. Data are evaluated by appropriate programs in the central device. Currents and volt-
ages 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. „pickup“, „tripping“ are also represented.
In the event of transfer to a central device, the request for data transfer can be executed automatically and can
be selected to take place after each pickup by the protection, or only after a tripping.
2.49.10.2Setting Notes
Fault Recording
Fault recording (waveform capture) will only take place if address 104 FAULT VALUE is set to Instant.
values or RMS values. Other settings pertaining to fault recording (waveform capture) are found under the
submenu OSC. FAULT REC. of the PARAMETER menu. Waveform capture makes a distinction between the
trigger instant for an oscillographic record and the criterion to save the record (address 401
WAVEFORMTRIGGER). Normally the trigger is the pickup of a protective element, i.e. when a protective element
picks up the time is 0. The criterion for saving may be both the device pickup (Save w. Pickup) or the device
trip (Save w. TRIP). A trip command issued by the device can also be used as trigger instant (Start w.
TRIP); in this case it is also the saving criterion.
A waveform capture includes in machine protection the complete course of a fault. An event of fault begins with
the pickup by any protective function and ends with the last dropout of a protective function.
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