GE UR Series Instruction Manual page 153

5 SETTINGS
GND DIST Z2 REACH:
This setting defines the reach of the zone. The angle of the reach impedance is entered as the
reach impedance is entered in secondary ohms.
GND DIST Z2 RCA:
The characteristic angle (similar to the "maximum torque angle" in previous technologies) of the ground distance character-
istic is specified by this setting. It is set as an angle of reach impedance as shown in the MHO DISTANCE CHARACTERIS-
TIC and QUAD DISTANCE CHARACTERISTIC figures. This setting is independent from the
(the characteristic angle of an extra directional supervising function).
GND DIST Z2 COMP LIMIT:
This setting shapes the operating characteristic. In particular, it enables a lens-shaped characteristic of the mho function
and a tent-shaped characteristic of the reactance boundary of the quad function.
If the mho shape is selected, the same limit angle applies to mho and supervising reactance comparators. In conjunction
with the mho shape selection, this setting improves loadability of the protected line. In conjunction with the quad character-
istic, this setting improves security for faults close to the reach point by adjusting the reactance boundary into a tent-shape.
GND DIST Z2 DIR RCA:
The characteristic angle (or "maximum torque angle") of the directional supervising function is selected by this setting. If the
MHO shape is applied, the directional function is an extra supervising function, as the dynamic mho characteristic itself is a
directional one. In conjunction with the quad shape selection, this setting defines the only directional function built into the
ground distance element. The directional function uses memory voltage for polarization.
GND DIST Z2 DIR COMP LIMIT:
This setting selects the comparator limit angle for the directional supervising function.
GND DIST Z2 QUAD RGT BLD:
This setting defines the right blinder position of the quad characteristic along the resistive axis of the impedance plane (see
the QUAD DISTANCE CHARACTERISTIC figure). The angular position of the blinder is adjustable with the use of the
setting.
DIST Z2 QUAD RGT BLD RCA
This setting applies only to the quad characteristic and should be set giving consideration to the maximum load current and
required resistive coverage.
GND DIST Z2 QUAD RGT BLD RCA:
This setting defines the angular position of the right blinder of the quad characteristic (see the QUAD DISTANCE CHARAC-
TERISTIC figure). This setting applies only to the quad characteristic.
GND DIST Z2 QUAD LFT BLD:
This setting defines the left blinder position of the quad characteristic along the resistive axis of the impedance plane (see
the QUAD DISTANCE CHARACTERISTIC figure). The angular position of the blinder is adjustable with the use of the
setting. This setting applies only to the quad characteristic and should be set with consideration
DIST Z2 QUAD LFT BLD RCA
to the maximum load current.
GND DIST Z2 QUAD LFT BLD RCA:
This setting defines the angular position of the left blinder of the quad characteristic (see the QUAD DISTANCE CHARAC-
TERISTIC figure). This setting applies only to the quad characteristic.
GND DIST Z2 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 conditions preventing maloperation due
to VT fuse failure.
GND DIST Z2 VOLT LEVEL:
This setting is relevant for applications on series-compensated lines, or in general, if series 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 bank configured under the
THEORY OF OPERATION chapter for more details, and the APPLICATION OF SETTINGS chapter for information on how
to calculate this setting for applications on series compensated lines.
GE Power Management L90 Line Differential Relay
5.5 GROUPED ELEMENTS
setting. The
GND DIST Z2 RCA
setting
GND DIST Z2 DIR RCA
GND
GND
. See the
DISTANCE SOURCE
5-69
5