10.2.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberOverfrequency protection SAPTOFf >SYMBOL-O V1 EN8110.2.2 FunctionalityOverfrequency protection function SAPTOF is applicable in all situations, wherereliable detection of high fundamental power system frequency is needed.Overfrequency occurs because of sudden load drops or shunt faults in the powernetwork. Close to the generating plant, generator governor problems can also causeover frequency.SAPTOF measures frequency with high accuracy, and is used mainly for generationshedding and remedial action schemes. It is also used as a frequency stage initiatingload restoring. A definite time delay is provided for operate.SAPTOF is provided with an undervoltage blocking.10.2.3 Function blockSAPTOFU3P*BLOCKTRIPSTARTBLKDMAGNIEC09000280_1_en.vsdIEC09000280 V1 ENFigure 105: SAPTOF function block10.2.4 SignalsTable 159:SAPTOF Input signalsName Type Default DescriptionU3P GROUPSIGNAL- Three phase group signal for voltage inputsBLOCK BOOLEAN 0 Block of function1MRK 504 135-UEN A Section 10Frequency protection235Technical manual
