Functions
2.44 Threshold supervision
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
306
2.44.2 Setting Notes
General
The threshold supervision function is only effective and accessible if address 185 THRESHOLD has been set to
Enabled during the configuration of the protection functions.
Pickup Values
The pickup values are set as percentages. Note the scaling factors listed in the Measured values table.
The measured values for power P, Q, ΔP and cosϕ as well as the phase angle can be either positive or nega-
tive. If a negative threshold value is to be monitored, the number line definition applies (–10 is smaller than –5).
Example:
The measured quantity P (active power) is allocated to MV1> and set to –5 %.
If the actual measured value is higher than –5 % (e.g. –4 % or even +100 %), the indication „Meas. Value1>“
is output as a logical „1“, which means a pickup in terms of protection engineering. A dropout signal (indication
„Meas. Value1>“ logical "0") is output if the measured value drops to less than –5 % · 1.05 = –5.25 %.
With the measured quantity P is allocated to MV2<, monitoring checks for an undershoot.
A pickup signal is output if the measured value becomes less than –5 % (e.g. –8 %). The dropout value is then
–5 % · 0.95 = –4.75 %.
Note
The measured values U
L1E
, U
L2E
, U
L3E
, U
E
, U
0
, U
1
, U
2
, U
E3h
, I
EE1
, I
EE2
3I
0
, I
1
, I
2
and measuring transducer 1
are always greater than 0. Care should be taken here to use only positive threshold values which allow the
indication to drop out.
With the power angle ϕ it should be kept in mind that this angle is only defined for ± 100 % (equivalent to ±
180°) or less. The threshold value should be chosen accordingly, taking into account the dropout ratio.
Further Processing of Indications
The indications of the 10 measured value monitoring blocks (see information overview) are available in the con-
figuration matrix for further logical processing by the CFC.
2.44.3 Settings
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