5-236
G60 Generator Protection System
GE Multilin
5.6 GROUPED ELEMENTS
5 SETTINGS
5
This element provides protection against energization while the generator is at standstill or reduced speed. The feature is
armed using either the AND or OR combination of the undervoltage and machine off-line conditions, selected with the
ACCDNT ENRG ARMING MODE
setting (see below). The undervoltage condition is determined from the measured voltages.
The machine off-line status is indicated by a dedicated FlexLogic operand. Once armed, the accidental energization feature
operates upon detecting an overcurrent condition in any of the stator phases.
This feature can also provide protection against poor synchronization.
•
ACCDNT ENRG ARMING MODE:
This setting specifies whether the feature gets armed by
either
of the undervoltage
or machine off-line conditions (“UV or Off-line” value), or by
both
the conditions (“UV and Off-line” value). In both
cases, the element is armed after 5 seconds of the appropriate condition and de-armed 250 ms after the arming condi-
tion (UV and/or Off-line) ceases.
The “UV or Off-line” selection shall be made when the VTs are on the power system side of the disconnecting device.
If this is the case, the measured voltages may be normal regardless of the status of the protected machine, thus the
need for an OR condition. The “UV or Off-line” value provides protection against poor synchronization. During normal
synchronization, there should be relatively low current measured. If however, synchronization is attempted when con-
ditions are not appropriate, a large current would be measured shortly after closing the breaker. Since this feature does
not de-arm immediately, but after a 250 ms time delay, this will result in operation under imprecise synchronization.
The
ACCDNT ENRG OC PICKUP
setting can control the required precision of synchronization.
The “UV and Off-line” value shall be made when the VTs are on the generator side of the disconnecting device. If this
is the case, both the undervoltage and machine off-line conditions are required to indicate that the protected generator
is not energized.
•
ACCDNT ENRG OC PICKUP:
This setting specifies the current level required to operate the armed Accidental Energi-
zation element. If any of the phase current is above the
ACCDNT ENRG OC PICKUP
level, the feature operates.
•
ACCDNT ENRG UV PICKUP:
This setting specifies the voltage level required to arm the Accidental Energization ele-
ment. All of the line-to-line voltages must drop below the
ACCDNT ENRG UV PICKUP
level in order to detect the undervolt-
age condition. The setting is entered in voltage pu values. As the element always responds to the line-to-line voltages,
care must be applied in picking up the value depending on the VT connection.
•
ACCDNT ENRG OFFLINE
: This setting specifies the FlexLogic™ operand indicating that the protected generator is
off-line.
Figure 5–124: ACCIDENTAL ENERGIZATION SCHEME LOGIC
830004A5.CDR
SETTING
FLEXLOGIC OPERANDS
FLEXLOGIC OPERAND
ACCDNT ENRG
FUNCTION:
ACCDNT ENRG OP
ACCDNT ENRG ARMED
ACCDNT ENRG DPO
Enabled = 1
AND
ACCDNT ENRG
BLOCK:
Off = 0
SETTING
ACCDNT ENRG OC
PICKUP:
IA > Pickup
IB > Pickup
IC > Pickup
SETTINGS
SETTINGS
ACCDNT ENRG UV
PICKUP:
RUN
RUN
RUN
RUN
RUN
RUN
VAB < Pickup
VBC < Pickup
VCA < Pickup
OR
AND
SETTING
VT CONNECTION
WYE
VAG - VBG
VBG - VCG
VCG - VAG
DELTA
VAB
VBC
VCA
IA
IB
IC
ACCDNT ENRG
OFFLINE:
ACCDNT ENRG
SOURCE:
ACCDNT ENRG
ARMING MODE:
UV or Offline = 1
Off = 0
SETTING
SETTING
OR
OR
5 s
0.25 s
AND
AND
AND
UV and Offline = 0
Summary of Contents for Multilin g60
Page 10: ...x G60 Generator Protection System GE Multilin TABLE OF CONTENTS INDEX ...
Page 32: ...1 22 G60 Generator Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 160: ...4 30 G60 Generator Protection System GE Multilin 4 3 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Page 486: ...5 326 G60 Generator Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 518: ...6 32 G60 Generator Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Page 532: ...7 14 G60 Generator Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Page 748: ...D 10 G60 Generator Protection System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Page 760: ...E 12 G60 Generator Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...