Data Storage For Fault Recording; Applying The Function Parameter Settings - Siemens siprotec 7SA6 User Manual

6.21.3 Data Storage for Fault Recording

6.21.4 Applying the Function Parameter Settings

Minimum,
Maximum and
Average Values
7SA6 Manual
C53000-G1176-C133-1
The distance protection 7SA6 has a fault recording memory. The instantaneous
values of the measured signals
i , i , i , i or i , and u
L1 L2 L3 E EE
(voltages according to type of connection) are sampled at an interval of 1 ms (at
50 Hz) respectively 0.83 ms (at 60 Hz), and stored in a circular shift register (20
samples per cycle). In the event of a fault the data is memorized for a selectable period
of time, not exceeding 5 s per fault. In a total period of approx. 15 s up to 8 fault
recordings can be memorized. The recording memory is automatically updated in the
event of a new system fault, thereby not requiring an acknowledgment. In addition to
storage of the fault recording by the protection fault detection, a recording may also be
initiated via binary input, the integrated keypad and display, or via the serial PC or
service 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
analysis software DIGRA 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. A selection may be made as to whether the currents
and voltages are represented 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. The evaluation of the data is done by applicable
programs in the central device. Currents and voltages are referred to their maximum
values, scaled to their rated values and prepared for graphic representation. In
addition, internal events are recorded as binary traces (marks), e.g. "fault detection",
"tripping".
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 fault detection by
the protection, or only after a trip.
In addresses  to  you can determine the time intervals for the calculation
of minimum, maximum and average values.
The tracking of minimum and maximum values can be reset automatically at a pre-
definied point in time. To select this feature, address 8311 0LQ0D[ F\F5(6(7 is set
to <HV. The point in time when reset is to take place (the minute of the day in which
reset will take place) is set in address 8312 0L0D 5(6(7 7,0(. The reset cycle (in
days) is entered at address 8313 0L0D 5(6(7&<&/(, and the date for starting the
cyclical process in days after completion of the configuration procedure is entered in
address 8314 0LQ0D[5(667$57.
The time interval for measured value averaging is set at address  '0'
,QWHUYDO. The first number specifies the averaging time window in minutes while the
second number determines the number of updates within the time window. A setting
of  0LQ  6XEV, for example, means that time averaging occurs for all
, u , u , u
L1 L2 L3 en
Functions
®
4 and the graphic
6-287