6-18L90 Line Differential RelayGE Power Management6.4 RECORDS 6 ACTUAL VALUES66.4 RECORDS 6.4.1 FAULT REPORTSPATH: ACTUAL VALUES ÖØ RECORDS Ö FAULT REPORTS ÖThe latest 10 fault reports can be stored. The most recent fault location calculation (when applicable) is displayed in thismenu, along with the date and time stamp of the event which triggered the calculation. See the SETTINGS Ö PRODUCTSETUP ÖØ FAULT REPORT menu for assigning the Source and Trigger for fault calculations. Refer to the COMMANDS ÖØCLEAR RECORDS menu for clearing fault reports.a) FAULT LOCATOR OPERATIONFault Type determination is required for calculation of Fault Location – the algorithm uses the angle between the negativeand positive sequence components of the relay currents. To improve accuracy and speed of operation, the fault compo-nents of the currents are used, i.e., the pre-fault phasors are subtracted from the measured current phasors. In addition tothe angle relationships, certain extra checks are performed on magnitudes of the negative and zero sequence currents.The single-ended fault location method assumes that the fault components of the currents supplied from the local (A) andremote (B) systems are in phase. The figure below shows an equivalent system for fault location.Figure 6–4: EQUIVALENT SYSTEM FOR FAULT LOCATIONThe following equations hold true for this equivalent system.eqn. 1where:m = sought pu distance to fault,Z = positive sequence impedance of the line.The currents from the local and remote systems can be parted between their fault (F) and pre-fault load (pre) components:eqn. 2and neglecting shunt parameters of the line:eqn. 3NO FAULTS TO REPORTor FAULT REPORT #FAULT # DATE:2000/08/11Range: YYYY/MM/DDMESSAGE FAULT # TIME:00:00:00.000000Range: HH:MM:SS.ssssssMESSAGE FAULT # TYPE:ABGwhere applicableMESSAGE FAULT # LOCATION00.0 kmwhere applicableMESSAGE FAULT # RECLOSESHOT: 0where applicablemZ (1 – m)ZRFZA ZBEA EBVA VBVFI A I BLocalBusRemoteBusdistance to faultV A m Z I A⋅ ⋅R F I A I B+( )⋅+=I A I AF I Apre+=I B I BF I Apre–=
