GE Multilin
D30 Line Distance Protection System
5-151
5 SETTINGS
5.6 GROUPED ELEMENTS
5
5.6.7 PHASE CURRENT
a) MAIN MENU
PATH: SETTINGS
GROUPED ELEMENTS
SETTING GROUP 1(6)
PHASE CURRENT
b) INVERSE TIME OVERCURRENT CURVE CHARACTERISTICS
The inverse time overcurrent curves used by the time overcurrent elements are the IEEE, IEC, GE Type IAC, and I
2
t stan-
dard curve shapes. This allows for simplified coordination with downstream devices.
If none of these curve shapes is adequate, FlexCurves may be used to customize the inverse time curve characteristics.
The definite time curve is also an option that may be appropriate if only simple protection is required.
A time dial multiplier setting allows selection of a multiple of the base curve shape (where the time dial multiplier = 1) with
the curve shape (
CURVE
) setting. Unlike the electromechanical time dial equivalent, operate times are directly proportional
to the time multiplier (
TD MULTIPLIER
) setting value. For example, all times for a multiplier of 10 are 10 times the multiplier 1
or base curve values. Setting the multiplier to zero results in an instantaneous response to all current levels above pickup.
Time overcurrent time calculations are made with an internal
energy capacity
memory variable. When this variable indi-
cates that the energy capacity has reached 100%, a time overcurrent element will operate. If less than 100% energy capac-
ity is accumulated in this variable and the current falls below the dropout threshold of 97 to 98% of the pickup value, the
variable must be reduced. Two methods of this resetting operation are available: “Instantaneous” and “Timed”. The “Instan-
taneous” selection is intended for applications with other relays, such as most static relays, which set the energy capacity
directly to zero when the current falls below the reset threshold. The “Timed” selection can be used where the relay must
coordinate with electromechanical relays.
IEEE CURVES:
The IEEE time overcurrent curve shapes conform to industry standards and the IEEE C37.112-1996 curve classifications
for extremely, very, and moderately inverse. The IEEE curves are derived from the formulae:
PHASE CURRENT
PHASE TOC1
MESSAGE
PHASE TOC2
MESSAGE
PHASE IOC1
MESSAGE
PHASE IOC2
MESSAGE
PHASE IOC3
MESSAGE
PHASE IOC4
MESSAGE
PHASE
DIRECTIONAL 1
MESSAGE
PHASE
DIRECTIONAL 2
Table 5–11: OVERCURRENT CURVE TYPES
IEEE
IEC
GE TYPE IAC
OTHER
IEEE Extremely Inverse
IEC Curve A (BS142)
IAC Extremely Inverse
I
2
t
IEEE Very Inverse
IEC Curve B (BS142)
IAC Very Inverse
FlexCurves A, B, C, and D
IEEE Moderately Inverse
IEC Curve C (BS142)
IAC Inverse
Recloser Curves
IEC Short Inverse
IAC Short Inverse
Definite Time
Summary of Contents for D30D00HCHF8AH6AM6BP8BX7A
Page 10: ...x D30 Line Distance Protection System GE Multilin TABLE OF CONTENTS...
Page 374: ...5 248 D30 Line Distance Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5...
Page 398: ...6 24 D30 Line Distance Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6...
Page 410: ...7 12 D30 Line Distance Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7...
Page 444: ...9 24 D30 Line Distance Protection System GE Multilin 9 5 FAULT LOCATOR 9 THEORY OF OPERATION 9...
Page 576: ...B 102 D30 Line Distance Protection System GE Multilin B 4 MEMORY MAPPING APPENDIX B B...
Page 616: ...D 10 D30 Line Distance Protection System GE Multilin D 1 IEC 60870 5 104 PROTOCOL APPENDIX D D...
Page 628: ...E 12 D30 Line Distance Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E...
Page 636: ...F 8 D30 Line Distance Protection System GE Multilin F 3 WARRANTY APPENDIX F F...
Page 646: ...x D30 Line Distance Protection System GE Multilin INDEX...
