GE D30 Instruction Manual page 290

5.6 GROUPED ELEMENTS
The reactance supervision for the mho function uses the zero-sequence current for polarization. The reactance line of the
quadrilateral function uses either zero-sequence or negative-sequence current as a polarizing quantity. The selection is
controlled by a user setting and depends on the degree of non-homogeneity of the zero-sequence and negative-sequence
equivalent networks.
The directional supervision uses memory voltage as polarizing quantity and both zero- and negative-sequence currents as
operating quantities.
The phase selection supervision restrains the ground elements during double-line-to-ground faults as they – by principles
of distance relaying – may be inaccurate in such conditions. Ground distance zones 1 and higher apply additional zero-
sequence directional supervision. See chapter 8 for additional details.
Each ground distance zone is configured individually through its own setting menu. All of the settings can be independently
modified for each of the zones except:
1. The
SIGNAL SOURCE

GROUPED ELEMENTS
2. The
MEMORY DURATION

TINGS GROUPED ELEMENTS
The common distance settings noted at the start of this section must be properly chosen for correct operation of the ground
distance elements.
Although all ground distance zones can be used as either instantaneous elements (pickup [
Logic signals) or time-delayed elements (operate [
under-reaching tripping mode.
Ensure that the
menu) is set correctly to prevent improper operation of associated memory action.
BANK
5
NOTE
• GND DIST Z1 DIR: All ground distance zones are reversible. The forward direction is defined by the
setting and the reverse direction is shifted by 180° from that angle. The non-directional zone spans between the for-
ward reach impedance defined by the
ance defined by the
• GND DIST Z1 SHAPE: This setting selects the shape of the ground distance characteristic between the mho and
quadrilateral characteristics. The selection is available on a per-zone basis.
The directional and non-directional quadrilateral ground distance characteristics are shown below. The directional and
non-directional mho ground distance characteristics are the same as those shown for the phase distance element in
the previous sub-section.
Figure 5–65: DIRECTIONAL QUADRILATERAL GROUND DISTANCE CHARACTERISTIC
5-154
setting (common for both phase and ground elements for all zones as entered under the
 
SETTING GROUP 1(6)
setting (common for both phase and ground elements for all zones as entered under the

SETTING GROUP 1(6)
OP
PHASE VT SECONDARY VOLTAGE
GND DIST Z1 REACH
and
GND DIST Z1 REV REACH
X
COMP LIMIT
DIR COMP LIMIT
LFT BLD RCA
-LFT BLD
D30 Line Distance Protection System
menu).
DISTANCE
 menu).
DISTANCE
] FlexLogic signals), only zone 1 is intended for the instantaneous
(see the

SETTINGS SYSTEM SETUP
and
GND DIST Z1 RCA
settings.
GND DIST Z1 REV REACH RCA
"+" NON-HOMOGEN. ANG
"-" NON-HOMOGEN. ANG
COMP LIMIT
DIR COMP LIMIT
DIR RCA
RCA
RGT BLD RCA
5 SETTINGS
] and dropout [
PKP DPO
 
AC INPUTS
GND DIST Z1 RCA
settings, and the reverse reach imped-
R
RGT BLD
837769A1.CDR
SETTINGS
SET-
] Flex-
VOLTAGE
GE Multilin