7.10.6 Monitored dataTable 149:ZGVPDIS Monitored dataName Type Values (Range) Unit DescriptionUL1 REAL - kV Voltage in phase L1UL2 REAL - kV Voltage in phase L2UL3 REAL - kV Voltage in phase L3IL1 REAL - A Current in phase L1IL2 REAL - A Current in phase L2IL3 REAL - A Current in phase L37.10.7 Operation principleThe full scheme backup distance element constitutes of three operating zones. Zone1has only the phase-to-phase loops enabled. Zone2 and zone3 can be selected for phase–to-phase or Enhanced reach loop. Each measuring loop use the offset mhocharacteristicThe base value of impedance can be calculated according to equation 53.3UBaseZBaseIBase=IECEQUATION1400024 V1 EN (Equation 53)Where,ZBase is the base value of impedanceUBase is the line-to-line voltage rating at the generator terminalIBase is the line current rating at the generator terminalThe minimum operating current is provided using the setting IMinOp.All the outputs will be blocked by activation of the BLOCK or BLKZ input.Offset mho characteristicZGVPDIS consists of three distance elements operated for three zones separately.Each zone consists of measuring loops which uses self-polarized offset mhocharacteristics with both forward and reverse reach settings for the detection of thefault in the respective zone. The operating characteristics of all the three zones areshown in Figure 146. The ImpedanceAngle setting is common to all three zones.Section 7 1MRK502052-UEN BImpedance protection322Technical manual
