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5 SETTINGS
•
PHS DIST Z1 RCA: This setting specifies the characteristic angle (similar to the 'maximum torque angle' in previous
technologies) of the phase distance characteristic for the forward and reverse applications. In the non-directional appli-
cations, this setting defines the angle of the forward reach impedance. The reverse reach impedance in the non-direc-
tional applications is set independently. The setting is an angle of reach impedance as shown in the distance
characteristic figures shown earlier. This setting is independent from
extra directional supervising function.
•
PHS DIST Z1 REV REACH: This setting defines the reverse reach of the zone set to non-directional (
setting). The value must be entered in secondary ohms. This setting does not apply when the zone direction is set to
"Forward" or "Reverse".
•
PHS DIST Z1 REV REACH RCA: This setting defines the angle of the reverse reach impedance if the zone is set to
non-directional (
PHS DIST Z1 DIR
"Reverse".
•
PHS DIST Z1 COMP LIMIT: This setting shapes the operating characteristic. In particular, it produces the lens-type
characteristic of the mho function and a tent-shaped characteristic of the reactance boundary of the quadrilateral func-
tion. If the mho shape is selected, the same limit angle applies to both the mho and supervising reactance compara-
tors. In conjunction with the mho shape selection, the setting improves loadability of the protected line. In conjunction
with the quadrilateral characteristic, this setting improves security for faults close to the reach point by adjusting the
reactance boundary into a tent-shape.
•
PHS DIST Z1 DIR RCA: This setting selects the characteristic angle (or maximum torque angle) of the directional
supervising function. If the mho shape is applied, the directional function is an extra supervising function as the
dynamic mho characteristic is itself directional. In conjunction with the quadrilateral shape, this setting defines the only
directional function built into the phase distance element. The directional function uses the memory voltage for polar-
ization. This setting typically equals the distance characteristic angle
•
PHS DIST Z1 DIR COMP LIMIT: Selects the comparator limit angle for the directional supervising function.
•
PHS DIST Z1 QUAD RGT BLD: This setting defines the right blinder position of the quadrilateral characteristic along
the resistive axis of the impedance plane (see the Quadrilateral distance characteristic figures). The angular position of
the blinder is adjustable with the use of the
quadrilateral characteristic and should be set giving consideration to the maximum load current and required resistive
coverage.
•
PHS DIST Z1 QUAD RGT BLD RCA: This setting defines the angular position of the right blinder of the quadrilateral
characteristic (see the Quadrilateral distance characteristic figures).
•
PHS DIST Z1 QUAD LFT BLD: This setting defines the left blinder position of the quadrilateral characteristic along the
resistive axis of the impedance plane (see the Quadrilateral distance characteristic figures). The angular position of the
blinder is adjustable with the use of the
lateral characteristic and should be set with consideration to the maximum load current.
•
PHS DIST Z1 QUAD LFT BLD RCA: This setting defines the angular position of the left blinder of the quadrilateral
characteristic (see the Quadrilateral distance characteristic figures).
•
PHS DIST Z1 SUPV: The phase distance elements are supervised by the magnitude of the line-to-line current (fault
loop current used for the distance calculations). For convenience,
being used, the entered value of the threshold setting is multiplied by
If the minimum fault current level is sufficient, the current supervision pickup should be set above maximum full load
current preventing maloperation under VT fuse fail conditions. This requirement may be difficult to meet for remote
faults at the end of zones 2 and above. If this is the case, the current supervision pickup would be set below the full
load current, but this may result in maloperation during fuse fail conditions.
•
PHS DIST Z1 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 where the zone shall not overreach. For plain
(non-compensated) lines, set to zero. Otherwise, the setting is entered in per unit of the phase VT bank configured
under the
DISTANCE SOURCE
tional applications (
PHS DIST Z1 DIR
directional zone. See chapters 8 and 9 for information on calculating this setting for series compensated lines.
•
PHS DIST Z1 DELAY: This setting allows the user to delay operation of the distance elements and implement stepped
distance protection. The distance element timers for zones 2 and higher apply a short dropout delay to cope with faults
GE Multilin
setting). This setting does not apply when the zone direction is set to "Forward" or
PHS DIST Z1 QUAD RGT BLD RCA
PHS DIST Z1 QUAD LFT BLD RCA
. Effectively, this setting facilitates dynamic current-based reach reduction. In non-direc-
set to "Non-directional"), this setting applies only to the forward reach of the non-
T60 Transformer Protection System
5.6 GROUPED ELEMENTS
, the characteristic angle of an
PHS DIST Z1 DIR RCA
.
PHS DIST Z1 RCA
setting. This setting applies only to the
setting. This setting applies only to the quadri-
3
is accommodated by the pickup (that is, before
3
).
PHS DIST Z1 DIR
5
5-151
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