17.2.7 Operation principle
GUID-4A46757C-EC5D-4BCE-9D09-C8152B062CE1 v2
The instantaneous output values of active and reactive power from the Measurements function
CVMMXN are used and integrated over a selected time
tEnergy
to measure the integrated energy.
Figure 577 shows the overall functionality of the energy calculation and demand handling function
ETPMMTR.
Zero Clamping
Detection
P
Q
Maximum Power
Demand Calculation
Energy Accumulation
Calculation
STARTACC
STOPACC
RSTDMD
MAXPAFD
MAXPARD
MAXPRFD
MAXPRRD
EAFALM
EARALM
ERFALM
ERRALM
EAFACC
EARACC
ERFACC
ERRACC
ACCINPRG
EAFPULSE
EARPULSE
ERFPULSE
ERRPULSE
RSTACC
IEC13000185-2-en.vsd
IEC13000185 V2 EN-US
Figure 577: ETPMMTR Functional overview logical diagram
The integration of energy values is enabled by the setting
EnaAcc
and controlled by the STARTACC
and STOPACC inputs. If the integration is in progress, the output ACCINPRG is high. Otherwise, it is
low. Figure 578 shows the logic of the ACCINPRG output. ACCINPRG is active when the STARTACC
input is active and the
EnaAcc
setting is enabled. When the RSTACC input is in the active state, the
output ACCINPRG is low even if the integration of energy is enabled. ACCINPRG is deactivated by
activating the STOPACC input.
T
F
STARTACC
ACCINPRG
RSTACC
³1
q
-1
STOPACC
&
FALSE
&
EnaAcc
IEC13000186-4-en.vsd
q
-1
= unit delay
IEC13000186 V4 EN-US
Figure 578: ACCINPRG Logic diagram
The accumulated energy values (in MWh and MVArh) are available as service values and also as
pulsed output depending on the
ExxAccPlsQty
setting, which can be connected to a pulse counter.
Accumulated energy outputs are available for forward as well as reverse direction. The
accumulated energy values can be reset to initial accumulated energy values (
ExxPrestVal
) from
the local HMI reset menu or with the input signal RSTACC. Figure 579 shows the logic for
integration of energy in active forward direction. Similarly, the integration of energy in active
reverse, reactive forward and reactive reverse is done.
1MRK 502 066-UUS B Section 17
Metering
1109
Technical manual
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