GE G60 Instruction Manual page 186

5.5 GROUPED ELEMENTS
• 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, producing the lens-type characteristic of
the mho function. The same limit angle applies to both the mho and supervising reactance comparators. This setting
improves loadability of the protected line.
5 • PHS DIST Z1 DIR RCA: This setting selects the characteristic angle (or maximum torque angle) of the directional
supervising function. The directional function is an extra supervising function as the dynamic mho characteristic itself is
a directional one. The directional function uses the memory voltage for polarization. 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 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 through 3. 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.
Zone 1 is sealed-in with the current supervision.
• 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 (
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 through 3 apply a short dropout delay to cope with faults
located close to the zone boundary when small oscillations in the voltages and/or currents could inadvertently reset the
timer. Zone 1 does not need any drop out delay since it is sealed-in by the presence of current.
• PHS DIST Z1 BLK: This setting enables the user to select a FlexLogic™ operand to block a given distance element.
VT fuse fail detection is one of the applications for this setting.
FLEXLOGIC OPERANDS
PH DIST Z1 PKP AB
PH DIST Z1 PKP BC
PH DIST Z1 PKP CA
PH DIST Z1 SUPN IAB
PH DIST Z1 SUPN IBC
PH DIST Z1 SUPN ICA
OPEN POLE OP *
NOTE: * D60 Only. Other UR models apply regular current seal-in for Z1.
5-88
setting). This setting does not apply when the zone direction is set to "Forward" or
.
PHS DIST Z1 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-
PHS DIST Z1 DIR
SETTING
PHS DIST Z1
DELAY:
t PKP
0
t PKP
0
t PKP
0
AND
AND
AND
Figure 5–42: PHASE DISTANCE ZONE 1 OP SCHEME
G60 Generator Management Relay
3 is accommodated by the pickup (i.e., before
3 ).
AND
OR
FLEXLOGIC OPERAND
AND
OR OR PH DIST Z1 OP
AND
OR
FLEXLOGIC OPERANDS
PH DIST Z1 OP AB
PH DIST Z1 OP BC
PH DIST Z1 OP CA
5 SETTINGS
837017A6.CDR
GE Multilin