GE Multilin
G60 Generator Protection System
5-269
5 SETTINGS
5.7 CONTROL ELEMENTS
5
5.7.8 FREQUENCY OUT-OF-BAND ACCUMULATION
a) GENERAL SETTINGS
PATH: SETTINGS
CONTROL ELEMENTS
FREQUENCY OOB ACCUMULATION
The turbine portion of a generator is designed to operate in a narrow frequency range around the nominal, typically ±5%.
As the turbine overspeeds (typically due to load rejection) or coasts down, the turbine will pass through operating frequen-
cies where the turbine blades find stimulus at their natural frequencies. Blade vibrations at these natural frequencies result
is stress on the blades that is accumulated and can result in cracking in some parts of the blade structure, most likely the tie
wires or blade covers. Though typically not catastrophic, the stress can change the vibration behavior of the blade so that
they can have natural resonances closer to the normal operating frequency. This element will provide diagnostic informa-
tion and alarms to the customer based on the accumulated off-nominal frequency operation time of a turbine over several
frequency bands and can then be used to schedule maintenance or other actions as desired by the customer.
The available setting of an upper and lower frequency for each band enables the user to overlap bands of frequencies in
the accumulation function. The accumulation function in any band can be blocked as desired. For example, accumulation
may be blocked during an out-of-service condition as set via an input to the relay.
The following settings are available and apply to all accumulators.
•
FREQ OOB ACCUM SOURCE
: This setting selects the source for the signal to be measured. The element first checks
for a live phase voltage available from the selected source. If voltage is not available, the element attempts to use a
phase current. If neither voltage nor current is available, the element will not operate, as it will not measure a parame-
ter below the minimum voltage/current setting.
•
FREQ OOB ACCUM MIN VOLT/AMP
: This setting specifies the minimum per-unit positive-sequence voltage or cur-
rent level required to allow the frequency out-of-band accumulators to operate. This threshold is used to prevent an
incorrect accumulation when operating quantity is too low.
•
FREQ ACCUM BLOCK
: This setting selects a FlexLogic operand to block out-of-band frequency accumulation in all
bands. This is typically required to avoid unnecessary accumulation when relay testing is being performed.
FREQUENCY OOB
ACCUMULATION
FREQ OOB ACCUM
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4
MESSAGE
FREQ OOB ACCUM MIN
VOLT/AMP: 0.10 pu
Range: 0.10 to 1.25 pu in steps of 0.01
MESSAGE
FREQ ACCUM BLOCK:
Off
Range: FlexLogic operand
MESSAGE
FREQ OOB ACCUM
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
FREQ OOB ACCUM
EVENTS: Disabled
Range: Enabled, Disabled
MESSAGE
FREQUENCY OOB
ACCUMULATOR 1
See following section.
MESSAGE
FREQUENCY OOB
ACCUMULATOR 2
See following section.
↓
MESSAGE
FREQUENCY OOB
ACCUMULATOR 7
See following section.
Содержание Multilin g60
Страница 10: ...x G60 Generator Protection System GE Multilin TABLE OF CONTENTS INDEX ...
Страница 32: ...1 22 G60 Generator Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Страница 130: ...3 68 G60 Generator Protection System GE Multilin 3 4 FIELD AND STATOR GROUND MODULES 3 HARDWARE 3 ...
Страница 160: ...4 30 G60 Generator Protection System GE Multilin 4 3 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Страница 486: ...5 326 G60 Generator Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Страница 518: ...6 32 G60 Generator Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Страница 532: ...7 14 G60 Generator Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Страница 538: ...8 6 G60 Generator Protection System GE Multilin 8 1 PHASE DISTANCE THROUGH POWER TRANSFORMERS 8 THEORY OF OPERATION 8 ...
Страница 748: ...D 10 G60 Generator Protection System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Страница 760: ...E 12 G60 Generator Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...