5-102 D30 Line Distance Relay GE Multilin5.5 GROUPED ELEMENTS 5 SETTINGS5Figure 5–52: GROUND DISTANCE ZONE 1 TO ZONE 3 SCHEME LOGICGROUND DIRECTIONAL SUPERVISION:A dual (zero and negative-sequence) memory-polarized directional supervision applied to the ground distance protectionelements has been shown to give good directional integrity. However, a reverse double-line-to-ground fault can lead to amaloperation of the ground element in a sound phase if the zone reach setting is increased to cover high resistance faults.Ground distance zones 2 through 3 use an additional ground directional supervision to enhance directional integrity. Theelement’s directional characteristic angle is used as a ‘maximum torque angle’ together with a 90° limit angle.The supervision is biased toward operation in order to avoid compromising the sensitivity of ground distance elements atlow signal levels. Otherwise, the reverse fault condition that generates concern will have high polarizing levels so that a cor-rect reverse fault decision can be reliably made.FLEXLOGIC OPERANDSSETTINGSSETTINGGND DIST Z1 PKP AGND DIST Z1 FUNCTION:GND DIST Z1 DPO AGND DIST Z1 PKP BGND DIST Z1 DPO BGND DIST Z1 PKP CGND DIST Z1 DPO CGND DIST Z1 PKP837029A3.CDRANDANDANDANDORGND DIST Z1 BLK:IAIBICDisable=0Off=0RUNRUNRUNA ELEMENTB ELEMENTC ELEMENTEnable=1I_2I_1I_0V_1SETTINGORDISTANCE SOURCE:INMEMORYV_1 > 0.80puI_1 > 0.025puSETTINGGND DIST Z1SUPV:RUN1 CYCLE1 CYCLEFLEXLOGIC OPERANDSGND DIST Z1 SUPN INGND DIST Z1 DIR SUPNVT CONNECTIONWYEVAG-VBGVBG-VCGVCG-VAGDELTAVABVBCVCAIN PICKUPSETTINGSGND DIST Z1 QUADRGT BLD:GND DIST Z1 QUADRGT BLD RCA: QUAD ONLYGND DIST Z1 QUADLFT BLD:GND DIST Z1 QUADLFT BLD RCA:GND DIST Z1 DIR:GND DIST Z1 COMP LIMIT:GND DIST Z1DIR COMP LIMIT:GND DIST Z1 SHAPE:GND DIST Z1 Z0/Z1 ANG:GND DIST Z1 REACH:GND DIST Z1 Z0/Z1 MAG:GND DIST Z1 RCA:GND DIST Z1 DIR RCA:GND DIST Z1 VOLTLEVEL:GND DIST Z1 Z0M/Z1 MAG:GND DIST Z1 Z0M/Z1 ANG:GND DIST Z1 REV REACHGND DIST Z1 POL CURRENT:GND DIST Z1 REV REACH RCA:GND DIST Z1NON-HOMOGEN ANG:
