CHAPTER 6: ACTUAL VALUES RECORDSG60 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6-296Loop impedance is defined as Z##=|Z##| Angle=R##+jX##, in secondary ohms and ## is the loop indication (AB, BC, CA,AG, BG, and CG respectively).They are calculated asEq. 6-5per the following equations.Eq. 6-6whereVA, VB, VC are phase voltage phasors in secondary voltsIA, IB, IC are current phasors in secondary ampsI0 is the zero sequence current phasors in secondary ampsIG is the ground current from the parallel line scaled to the source phase CT in secondary ampsZ0/Z1 is the zero sequence impedance to positive sequence impedance ratioZ0M/Z1 is mutual zero sequence impedance to positive sequence impedance ratio, both are settings taken from the firstenabled ground distance zone (count from zone 1 to zone 5)ZAG, ZBG, ZCG are calculated only if at least one ground distance zone is enabled; otherwise all the metering quantities forground distance impedance (ZAG, ZBG, and ZCG) are reset to zero, including magnitude and angle. Note that VTs of thedistance source must be connected in Wye if the ground distance element is enabled.6.5 Records6.5.1 User-programmable fault reportsACTUAL VALUES RECORDS USER-PROGRAMMABLE FAULT REPORTSThis menu displays the user-programmable fault report actual values. See the User-Programmable Fault Report section inchapter 5 for information on this feature. CG LOOP IMPEDANCEANGLE: 0.00 DEG USER-PROGRAMMABLE FAULT REPORTS NEWEST RECORDNUMBER: 0 LAST CLEARED DATE:2002/8/11 14:23:57 LAST REPORT DATE:2002/10/09 08:25:27
