GE Multilin
G60 Generator Protection System
9-3
9 APPLICATION OF SETTINGS
9.1 SETTING EXAMPLE
9
9.1.5 STATOR DIFFERENTIAL
The “LINE” and “NEUTRL” sources are both required for the stator differential element. The minimum pickup can usually be
set as low as 0.05 pu (corresponding to 0.25 A secondary or 400 A primary in this example). Set the
STATOR DIFF SLOPE 1
setting to accommodate for CT errors; a setting of 10% is adequate in most instances. Set the
STATOR DIFF SLOPE 2
setting
to accommodate for errors due to CT saturation; a setting of 80% is recommended for most applications. The
STATOR DIFF
BREAK 1
setting must be greater than the maximum load expected for the machine. The
STATOR DIFF BREAK 2
setting should
be set at the level where CT saturation is expected to occur.
Make the following parameter changes in EnerVista UR Setup or through the
SETTINGS
GROUPED ELEMENTS
SET-
TING GROUP 1
STATOR DIFFERENTIAL
menu:
9.1.6 GENERATOR UNBALANCE
Stage 1 of the generator unbalance element is typically used to trip the generator. In this example, the
I
2
capability of the
machine is 8% and the
I
2
2
T
capability is 10. The generator nominal current is:
(EQ 9.5)
The minimum operate time of stage 1 will be set to 0.25 seconds, the maximum operating time will be 10 minutes, and the
reset time will be set to 4 minutes.
Stage 2 is typically set lower than stage 1 with a time delay to prevent nuisance alarms for external faults that are normally
cleared by system protection. For the application example, the pickup setting is:
(EQ 9.6)
Source 2 will be chosen for this element. The settings are as follows:
I
nom
pu
( )
I
nom
primary
CT primary
---------------------------------
6800 A
8000 A
-------------------
0.85 pu
=
=
=
Pickup
70%
I
2
capability
×
0.70 8%
×
5.6%
=
=
=
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 ...