ABB Relion 670 Series Applications Manual page 114

Section 6
Wide area measurement system
IEC140000132 V2 EN-US
Figure 47: An example of wrong connection of 3PHSUM and PHASORREPORT blocks in
If settings for PMUREPORT instances (PHASORREPORT1 instances 1 and 2 above) differ for
SvcClass or ReportRate, then the synchrophasor reported by PHASOR2 connection from
PHASORREPORT1 instance 2 will not be compliant with IEEE C37.118 standard. The reason is as
in the rule 2, the filtering in SMAI/3PHSUM block is adapted according to the performance
class (SvcClass) and reporting rate of the connected instance of PHASORREPORT function
block. On the other hand, when 3PHSUM uses external DFT reference, it also adapts its filtering
according to the SMAI reference block. Therefore, in order to avoid two different filtering
applied to the 3PHSUM block, both SMAI reference block and 3PHSUM shall be connected to
the same PHASORREPORT instance. In this example (Figure 47), SMAI3 adapts its filtering
according to PHASORREPORT1 instance 2 (due to connection) and 3PHSUM is adapting its
filtering according to PHASORREPORT1 instance 1. On the other hand, since 3PHSUM is set to
receive external DFT reference from SMAI3, therefore If settings for PHASORREPORT1
instances 1 and 2 above differ for SvcClass or ReportRate, then 3PHSUM block will be affected
by two different filtering at the same time which is not possible. For example in Figure 47,
PHASOR2 from PHASORREPORT1 instance 1 may not be fully compliant with IEEE C37.118
standard.
Note: If the SMAI reference block is not connected to any PHASORREPORT block, then 3PHSUM
block can be freely connected to any PHASORREPORT block regardless of its DFT reference
setting.
Note: If more 3PHSUM blocks need to be used, all 3PHSUM blocks (using external DFT ref) have
to be connected to the same instance of PHASORREPORT blocks (PHASOR1-32 of Instance
number 1 or 2).
Note: If settings SvcClass and ReportRate are the same for different instances of
PHASORREPORT blocks, then 3PHSUM block can be freely connected to any of them regardless
of 3PHSUM block DFT reference setting or the reference SMAI block connection.
Note: Violation of rules 2 or 3 results in non-compliancy with IEEE C37.118 standard for some of
the synchrophasors. In case of rule 2 violation, the non-compliancy only applies to
synchrophasors from instance 2 and the synchrophasors from instance 1 will be still compliant.
The non-compliancy with the standard may be quite obvious as in case of rule 2 violation with
different SvcClass settings. This produces big angle error. On the other hand, it may be
difficult to detect the non-compliancy with the standard if rule 2 is violated with different
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IEC140000132-2-en.vsd
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