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Outline of automatic supervision
In power system, the protection function is not required to operate during normal conditions.
That is, the protection function should stay silent for the unfaulty conditions, but it has to start
respond immediately upon the occurrence of the fault. Therefore, as for the operation of the
protection system, the detection of an unhealthy condition, such as malfunction or errors in
the hardware or in the software, is requisite within the IED. The automatic supervision
function is designed to detect the unhealthy condition within the IED; the following concepts
are taken into account:
➢ The operating performance of the protection system should not be distorted.
➢ Supervision should be carried out by itself without any failure whenever
possible.
➢ The protection system should identify the fault instantly upon its occurrence.
Tips: The alarms can be blocked when Off is set for the switch [A.M.F]. It can be used to
remove alarms during testing. See
more information (→p. 1024).
Error levels
(i)
In the applications and the hardware, the number of items are supervised for detecting the
operation failure; hence, the results of the supervision functions are grouped and they are
classified into five error-levels to identify the error degree directly: warning (level 5=the minor
error) to the serious error (level 1=the critical error). Incidentally, zero (level 0) can be
identified as no error. Table 10.1-1 shows the errors grouped by the error degree. The groupings
are provided, for setting the degree of error, the user can select an user-defined degree for each
error occurs randomly. If a number of failures occur on several levels at same time, the
automatic supervision function selects the critical error among them to represent the error
inside the IED.
Table 10.1-1 Meanings and error degree in the supervision function
Levels
Degree of error
0
No error
1‡
Serious
2†‡
Serious (Comm.)
3†‡
Minor
4
Alarm
5
Warning
†Note: Level 2 and level 3 are shown, but the difference between the level 2 and the level
3 not given; thus, we can take the both having the same degree.
‡Note: The IEC 61850quality value is also changed depending on the level. See Chapter
Communication protocol: IEC 61850 communication: Quality signal
Chapter User interface: Test sub-menu
Example failures and errors
Fatal failures such as the memory errors within the IED
Failures on tele-communication
Failure on LAN (Ethernet) communication
Minor errors such as invalid errors by the user using settings
Detection of warnings classified by the user using settings
- 799 -
No error exists
6F2T0207 (0.01)
for
(→p. 905).
GRE200 (5,6)
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