Siemens siprotec 7SJ63, Инструкция по эксплуатации

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Functions
6-151
7SJ63 Manual
C53000-G1140-C120-1
Figure 6-63 Voltage Symmetry Monitoring
Current and Volt-
age Rotation To detect swapped phase connections in the voltage and current input circuits, the
phase sequence of the phase-to-phase measured voltages and the phase currents
are checked by the monitoring.
Direction measurement with normal voltages, path selection for fault location, and
negative sequence detection all assume a phase sequence of “abc”. The phase se-
quence of the phase-to-ground voltages is verified by ensuring the following
V
a
leads V
b
leads V
c
leads V
a
Likewise, the phase sequence of the phase currents is verified by ensuring the follow-
ing
I
a
leads I
b
leads I
c
leads I
a
Verification of the voltage rotation occurs when each measured voltage is at least
| V
c
|, |V
b
|, | V
a
| > 40V /
√
3.
Verification of the current rotation occurs when each measured current is at least
|I
a
|, |I
b
|, |I
c
| > 0.5 I
N
.
For abnormal phase sequences, the messages “
)DLO3K6HT9
” or “
)DLO3K
6HT,
” are issued, along with the switching of this message “
)DLO3K6HT
” to
the substation control system (SCADA).
For applications in which an opposite phase sequence is expected, the protective re-
lay should be adjusted via a binary input or a programmable setting. If the phase se-
quence is changed in the relay, phases ‘b’ and ‘c’ internal to the relay are reversed,
and the positive and negative sequence currents are thereby exchanged (see also
Section 6.16). The phase- related messages, malfunction values, and measured val-
ues are not affected by this.
6.17.2 Programming Settings for Measured Values Monitoring
Measured value monitoring can be turned on or off at address
0($685(68
3(59
. In addition, the sensitivity of measured value monitor can be modified. Default
values are set at the factory, which are sufficient in most cases. If especially high op-
erating asymmetry in the currents and/or voltages is to be expected for the application,
or if it becomes apparent during operation that certain monitoring functions activate
sporadically, then the setting should be less sensitive.
v
min
V
%$/$1&(9²/,0,7
Increase:
%$/)$&7259
V
max
V
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