GE Multilin g60, Instruction Manual

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GE Multilin G60 Generator Protection System 5-165
5 SETTINGS 5.6 GROUPED ELEMENTS
5
• PHS DIST Z1 REV REACH : This setting defines the reverse reach of the zone set to non-directional (
PHS DIST Z1 DIR
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
setting). This setting does not apply when the zone direction is set to “Forward” or
“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.
• 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 RCA
.
• 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, 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, 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
. Effectively, this setting facilitates dynamic current-based reach reduction. In non-direc-
tional applications (
PHS DIST Z1 DIR
set to “Non-directional”), this setting applies only to the forward reach of the non-
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
located close to the zone boundary when small oscillations in the voltages 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.
Figure 5–70: PHASE DISTANCE ZONE 1 OP SCHEME
3
3
** D60, L60, and L90 only. Other UR-series models apply regular current seal-in for zone 1.
OR OR
OR
OR
AND
AND
AND
AND
AND
AND
837017A8.CDR
FLEXLOGIC OPERAND
PH DIST Z1 PKP AB
PH DIST Z1 SUPN IAB
PH DIST Z1 SUPN IBC
PH DIST Z1 SUPN ICA
OPEN POLE OP **
FLEXLOGIC OPERANDS
SETTING
PH DIST Z1 DELAY
T
PKP
0
T
PKP
0
T
PKP
0
FLEXLOGIC OPERAND
PH DIST Z1 PKP BC
FLEXLOGIC OPERAND
PH DIST Z1 PKP CA
PH DIST Z1 OP AB
PH DIST Z1 OP BC
PH DIST Z1 OP CA
FLEXLOGIC OPERANDS
PH DIST Z1 OP
FLEXLOGIC OPERANDS