fulfilled again within a defined reset time, the START output is reset after the resettime has elapsed.After an issue of the TRIP output signal, the RESTORE output of SAPFRC is set aftera time delay (tRestore), when the measured frequency has returned to the levelcorresponding to RestoreFreq. If tRestore is set to 0.000 s the restore functionality isdisabled, and no output will be given. The restore functionality is only active forlowering frequency conditions and the restore sequence is disabled if a new negativefrequency gradient is detected during the restore period.10.3.6.3 DesignIEC08000009_en_1.vsdRESTORESTART STARTTRIPStart&TripOutputLogicBLOCKFrequency100 msComparatorIf[StartFreqGrad<0ANDdf/dt < StartFreqGrad]OR[StartFreqGrad>0ANDdf/dt > StartFreqGrad]ThenSTARTComparatorf > RestoreFreqORDefinite Time DelaytTriptRestoreBLKDMAGNRate-of-Changeof FrequencyBLOCKfreqNotValidIEC08000009 V1 ENFigure 155: Schematic design of Rate-of-change frequency protection SAPFRC1MRK 502 048-UEN A Section 10Frequency protection305Technical manual
