2 Functions
186
7UM61 Manual
C53000-G1176-C127-3
The measured values for power P, Q and ∆P as well as the phase angle, can be either
positive or negative. 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 in-
dication “Meas. Value1>” is output as a logical "1", which from the protection point
of view corresponds to a pickup. 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 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 U1, U2, I0, I1 and I2 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 accord-
ingly, taking into account the dropout ratio.
Further Processing
of Indications
The indications of the 6 measured value monitoring blocks (see information list) are
available in the configuration matrix for further logical processing by the CFC.
2.30.3 Settings
Addr. Parameter Setting Options Default Setting Comments
8501 MEAS. VALUE 1> Disabled
P
Q
Delta P
U1
U2
I0
I1
I2
PHI
Disabled Measured Value for Threshold
MV1>
8502 THRESHOLD MV1> -200 .. 200 % 100 % Pickup Value of Measured Value
MV1>
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