adapted according to the performance class (SvcClass) and reporting rate of the connectedinstance of PHASORREPORT function block. On the other hand, when 3PHSUM usesexternal 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, bothSMAI reference block and 3PHSUM shall be connected to the same PHASORREPORTinstance. In this example (Figure 47), SMAI3 adapts its filtering according toPHASORREPORT1 instance 2 (due to connection) and 3PHSUM is adapting its filteringaccording to PHASORREPORT1 instance 1. On the other hand, since 3PHSUM is set toreceive external DFT reference from SMAI3, therefore If settings forPHASORREPORT1 instances 1 and 2 above differ for SvcClass or ReportRate, then3PHSUM block will be affected by two different filtering at the same time which is notpossible. For example in Figure 47, PHASOR2 from PHASORREPORT1 instance 1 maynot be fully compliant with IEEE C37.118 standard.Note: If the SMAI reference block is not connected to any PHASORREPORT block, then3PHSUM block can be freely connected to any PHASORREPORT block regardless of itsDFT reference setting.Note: If more 3PHSUM blocks need to be used, all 3PHSUM blocks (using external DFTref) 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 ofPHASORREPORT blocks, then 3PHSUM block can be freely connected to any of themregardless of 3PHSUM block DFT reference setting or the reference SMAI blockconnection.Note: Violation of rules 2 or 3 results in non-compliancy with IEEE C37.118 standard forsome of the synchrophasors. In case of rule 2 violation, the non-compliancy only appliesto synchrophasors from instance 2 and the synchrophasors from instance 1 will be stillcompliant. The non-compliancy with the standard may be quite obvious as in case of rule2 violation with different SvcClass settings. This produces big angle error. On the otherhand, it may be difficult to detect the non-compliancy with the standard if rule 2 is violatedwith different ReportRates, or if rule 3 is violated. In such cases, the synchrophasors mayonly fail to comply (with small error) in some particular test case(s).For more information regarding 3PHSUM block application, please refer to theApplication Manual under section Basic IED functions.6.2.4 Setting guidelinesBased on the functionality and appearance in PCM600, the PMU reporting functionalityis categorized into 4 different categories (function block) as follows:1MRK 506 369-UUS - Section 6Wide area measurement systemLine distance protection REL670 2.2 ANSI 129Application manual
