ABB REB670 Applications Manual page 477

1MRK 505 337-UUS -
Application manual
and so on – 244 values in total). Besides the block "group name", the analog inputs type
(voltage or current) and the analog input names that can be set directly in ACT.
Application functions should be connected to a SMAI block with same task cycle as the
application function, except for e.g. measurement functions that run in slow cycle tasks.
DFTRefExtOut: Parameter valid only for function block SMAI1 .
Reference block for external output (SPFCOUT function output).
DFTReference: Reference DFT for the SMAI block use.
These DFT reference block settings decide DFT reference for DFT calculations. The
setting InternalDFTRef will use fixed DFT reference based on set system frequency.
DFTRefGrp(n) will use DFT reference from the selected group block, when own group is
selected, an adaptive DFT reference will be used based on calculated signal frequency
from own group. The setting ExternalDFTRef will use reference based on what is
connected to input DFTSPFC.
The setting ConnectionType: Connection type for that specific instance (n) of the SMAI
(if it is Ph-N or Ph-Ph). Depending on connection type setting the not connected Ph-N or
Ph-Ph outputs will be calculated as long as they are possible to calculate. E.g. at Ph-Ph
connection A, B and C will be calculated for use in symmetrical situations. If N
component should be used respectively the phase component during faults I
connected to input 4.
Negation: If the user wants to negate the 3ph signal, it is possible to choose to negate only
the phase signals Negate3Ph, only the neutral signal NegateN or both Negate3Ph+N.
negation means rotation with 180° of the vectors.
GlobalBaseSel: Selects the global base value group used by the function to define (IBase),
(VBase) and (SBase).
MinValFreqMeas: The minimum value of the voltage for which the frequency is
calculated, expressed as percent of VBase (for each instance n).
Settings DFTRefExtOut and DFTReference shall be set to default value
InternalDFTRef if no VT inputs are available.
Even if the user sets the AnalogInputType of a SMAI block to "Current",
the MinValFreqMeas is still visible. However, using the current channel
values as base for frequency measurement is not recommendable for a
number of reasons, not last among them being the low level of currents
that one can have in normal operating conditions.
Section 18
Basic IED functions
/V must be
N N
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