9. SetVDepMode toSlope (default value).10. SetVDepFact to the value 25% (default value).11. SetVHighLimit to the value 100% (default value).All other settings can be left at the default values.7.17.3.3 Overcurrent protection with undervoltage seal-in GUID-B58E1CD6-F9AE-4301-ABE7-90DBFC987D69 v6To obtain this functionality, the IED application configuration shall include a logic in accordance tofigure 91 and, of course, the relevant three-phase generator currents and voltages shall beconnected to VRPVOC. Let us assume that, taking into account the characteristic of the generator,the excitation system and the short circuit study, the following settings are required:• Pickup current of the overcurrent stage: 150% of generator rated current at rated generatorvoltage;• Pickup voltage of the undervoltage stage: 70% of generator rated voltage;• Trip time: 3.0 s.The overcurrent stage and the undervoltage stage shall be set in the following way:1. SetOperation toEnabled.2. SetGlobalBaseSel to the right value in order to select the Global Base Values Group withVBase andIBase equal to the rated phase-to-phase voltage and the rated phase current of thegenerator.3. SetStartCurr to the value150%.4. SetCharacteristic toIEC Def. Time.5. SettDef_OC to6000.00 s, if no trip of the overcurrent stage is required.6. SetVDepFact to the value100% in order to ensure that the pickup value of the overcurrentstage is constant, irrespective of the magnitude of the generator voltage.7. SetOperation_UV toEnabled to activate the undervoltage stage.8. SetStartVolt to the values70%.9. SettDef_UV to3.0 s.10. SetEnBlkLowV toDisabled (default value) to disable the cut-off level for low-voltage of theundervoltage stage.The other parameters may be left at their default value.Section 7 1MRK 511 358-UUS ACurrent protection200Application manual
