Ud>U1U2To ProtectionTo ExcitationGen en06000389.vsdIEC06000389 V1 EN-USFigure 292: Supervision of fuses on generator circuit voltage transformers10.5.3 Setting guidelines SEMOD153915-5 v3The parameters for the voltage differential function are set via the local HMI orPCM600.The following settings are done for the voltage differential function.Operation: Off/OnGlobalBaseSel: Selects the global base value group used by the function to defineIBase, UBase and SBase as applicable.BlkDiffAtULow: The setting is to block the function when the voltages in thephases are low.RFLx: Is the setting of the voltage ratio compensation factor where possibledifferences between the voltages is compensated for. The differences can be due todifferent voltage transformer ratios, different voltage levels e.g. the voltagemeasurement inside the capacitor bank can have a different voltage level but thedifference can also e.g. be used by voltage drop in the secondary circuits. Thesetting is normally done at site by evaluating the differential voltage achieved as aservice value for each phase. The factor is defined as U2 · RFLx and shall be equalto the U1 voltage. Each phase has its own ratio factor.Section 10 1MRK 506 369-UEN BVoltage protection554 Line distance protection REL670 2.2 IECApplication manual
