GE Multilin D30 Line Distance Relay 5-1015 SETTINGS 5.5 GROUPED ELEMENTS5• GND DIST Z1 QUAD RGT BLD RCA: This setting defines the angular position of the right blinder of the quadrilateralcharacteristic (see the Quadrilateral distance characteristic figure).• GND DIST Z1 QUAD LFT BLD: This setting defines the left blinder position of the quadrilateral characteristic along theresistive axis of the impedance plane (see the Quadrilateral distance characteristic figure). The angular position of theblinder is adjustable with the use of the GND DIST Z1 QUAD LFT BLD RCA setting. This setting applies only to the quadri-lateral characteristic and should be set with consideration to the maximum load current.• GND DIST Z1 QUAD LFT BLD RCA: This setting defines the angular position of the left blinder of the quadrilateralcharacteristic (see the Quadrilateral distance characteristic figure).• GND DIST Z1 SUPV: The ground distance elements are supervised by the magnitude of the neutral (3I_0) current.The current supervision pickup should be set above the maximum unbalance current under maximum load conditionspreventing maloperation due to VT fuse failure.• GND DIST Z1 VOLT LEVEL: This setting is relevant for applications on series-compensated lines, or in general, ifseries capacitors are located between the relaying point and a point for which the zone shall not overreach. For plain(non-compensated) lines, this setting shall be set to zero. Otherwise, the setting is entered in per unit of the VT bankconfigured under the DISTANCE SOURCE. Effectively, this setting facilitates dynamic current-based reach reduction. Innon-directional applications (GND DIST Z1 DIR set to “Non-directional”), this setting applies only to the forward reach ofthe non-directional zone. See Chapter 8 and 9 for additional details and information on calculating this setting value forapplications on series compensated lines.• GND DIST Z1 DELAY: This setting enables the user to delay operation of the distance elements and implement astepped distance backup protection. The distance element timer applies a short drop out delay to cope with faultslocated close to the boundary of the zone when small oscillations in the voltages or currents could inadvertently resetthe timer.• GND DIST Z1 BLK: This setting enables the user to select a FlexLogic™ operand to block the given distance element.VT fuse fail detection is one of the applications for this setting.Figure 5–51: GROUND DISTANCE Z1 TO Z3 OP SCHEMEFLEXLOGIC OPERANDSFLEXLOGIC OPERANDFLEXLOGIC OPERANDSSETTING20 msec20 msec20 msecORtttPKPPKPPKPGND DIST Z1 PKP AGND DIST Z1 PKP BGND DIST Z1 PKP CGND DIST Z1 OP AGND DIST Z1 OP BGND DIST Z1 OP CGND DIST Z1 OPGND DIST Z1DELAY:837030A1.CDR
