GE L60 Instruction Manual page 367

CHAPTER 5: SETTINGS GROUPED ELEMENTS
— This setting specifies the shape the operating characteristic. In particular, it produces the lens-
PHS DIST Z1 COMP LIMIT
type characteristic of the mho function and a tent-shaped characteristic of the reactance boundary of the quadrilateral
function. If the mho shape is selected, the same limit angle applies to both the mho and supervising reactance
comparators. 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.
— This setting selects the characteristic angle (or maximum torque angle) of the directional supervising
PHS DIST Z1 DIR RCA
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 polarization. This
setting typically equals the distance characteristic angle .
PHS DIST Z1 RCA
— Selects the comparator limit angle for the directional supervising function.
PHS DIST Z1 DIR COMP LIMIT
— This setting defines the right blinder position of the quadrilateral characteristic along the
PHS DIST Z1 QUAD RGT BLD
resistive axis of the impedance plane (see the Quadrilateral Phase Distance Characteristic figures). The angular position of
the blinder is adjustable with the use of the setting. This setting applies only to the
PHS DIST Z1 QUAD RGT BLD RCA
quadrilateral characteristic and is set giving consideration to the maximum load current and required resistive coverage.
— This setting defines the angular position of the right blinder of the quadrilateral
PHS DIST Z1 QUAD RGT BLD RCA
characteristic (see the Quadrilateral Distance Characteristic figures).
— This setting defines the left blinder position of the quadrilateral characteristic along the
PHS DIST Z1 QUAD LFT BLD
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 setting. This setting applies only to the quadrilateral
PHS DIST Z1 QUAD LFT BLD RCA
characteristic and is set with consideration to the maximum load current.
— This setting defines the angular position of the left blinder of the quadrilateral
PHS DIST Z1 QUAD LFT BLD RCA
5
characteristic (see the Quadrilateral Distance Characteristic figures).
— The phase distance elements are supervised by the magnitude of the line-to-line current (fault loop
PHS DIST Z1 SUPV
current used for the distance calculations). For convenience, is accommodated by the pickup (that is, before being
used, the entered value of the threshold setting is multiplied by ).
If the minimum fault current level is sufficient, set the current supervision pickup above maximum full load current
preventing maloperation under VT fuse fail conditions. This requirement can be difficult to meet for remote faults at the
end of zones 2 and above. If this is the case, set the current supervision pickup below the full load current, but this can
result in maloperation during fuse fail conditions.
— This setting is relevant for applications on series-compensated lines, or in general, if series
PHS DIST Z1 VOLT LEVEL
capacitors are located between the relaying point and a point where the zone does 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
. Effectively, this setting facilitates dynamic current-based reach reduction. In non-directional
DISTANCE SOURCE
applications ( set to "Non-directional"), this setting applies only to the forward reach of the non-directional
PHS DIST Z1 DIR
zone. See the Application of Settings chapter for information on calculating this setting for series compensated lines.
— This setting allows the user to delay operation of the distance elements and implement stepped
PHS DIST Z1 DELAY
distance protection. The distance element timers for zones 2 and higher apply a short dropout delay to cope with faults
located close to the zone boundary when small oscillations in the voltages or currents can inadvertently reset the timer.
Zone 1 does not need any drop-out delay since it is sealed-in by the presence of current.
— This setting enables the user to select a FlexLogic operand to block a given distance element. VT fuse fail
PHS DIST Z1 BLK
detection is one of the applications for this setting.
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL 5-199