Siemens SIPROTEC 6MD665, Manual

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2.5 Metered Value Processing
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6MD665 Manual
C53000-G1876-C103-3
2.5 Metered Value Processing
The device can add up couner pulses of an external counter recorded via a binary
input. Additionally, the bay control unit can calculate energy values from measured
values.
2.5.1 Description
Operation of pulse
metered value The Bay Processing Unit 6MD665 forms the metered value as a sum of the externally
generated counter pulses of a power meter. The pulses are read in via a binary input.
The metered value receives a unit based on the following table. It has the same pre-
cision as the external counter and can also be an adjusted metered value.
Operation of
metered values cal-
culated from mea-
sured values With the metered values calculated from measured values , the Bay Processing Unit
6MD665 forms the power from the applied current and voltage values or from any
desired measured values and integrates this calculated power value over time. The
result is an energy value with the precision of the device (0.5 %), i.e. an operating
metered value which cannot be used for adjustment.
Table 2-4 Operating metered values
The following types of information can be allocated to a metered value window in the
DIGSI
®
allocation matrix.
• Metered values calculated from measured values
• Pulse metered value
The same operations are possible with pulse and metered values calculated from
measured values, e.g. reset - to set back to a specified value etc..
Using the pulse metered value
In this example, the active power of a 3-phase system is to be integrated over time and
displayed as a metered value. The pulse output of an external device which supplies
the active power pulse accordingly, is to be applied to a binary input of the device. The
power corresponding to a pulse must be known.
Inserting a pulse
metered value Open the allocation matrix of the device and select Only measured and metered
values as the information type.
Create the group Energy in the allocation matrix.
Open the information catalog and select the line PowerMeter (MVMV) under Power-
Meter
→
PowerMeter.
Measured values Possible units
W
p
+ Real power, output kWh, MWh, GWh
W
p
– Real power, input kWh, MWh, GWh
W
q
+ Reactive power, output kVARh, MVARh, GVARh
W
q
– Reactive power, input kVARh, MVARh, GVARh