GE Multilin
F60 Feeder Protection System
5-121
5 SETTINGS
5.5 GROUPED ELEMENTS
5
c) NEUTRAL INSTANTANEOUS OVERCURRENT
(ANSI 50N)
PATH: SETTINGS
ÖØ
GROUPED ELEMENTS
Ö
SETTING GROUP 1(6)
ÖØ
NEUTRAL CURRENT
ÖØ
NEUTRAL IOC1(2)
The neutral instantaneous overcurrent element may be used as an instantaneous function with no intentional delay or as a
definite time function. The element essentially responds to the magnitude of a neutral current fundamental frequency pha-
sor calculated from the phase currents. A positive-sequence restraint is applied for better performance. A small portion
(6.25%) of the positive-sequence current magnitude is subtracted from the zero-sequence current magnitude when forming
the operating quantity of the element as follows:
(EQ 5.16)
The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious zero-sequence currents
resulting from:
•
System unbalances under heavy load conditions
•
Transformation errors of current transformers (CTs) during double-line and three-phase faults.
•
Switch-off transients during double-line and three-phase faults.
The positive-sequence restraint must be considered when testing for pickup accuracy and response time (multiple of
pickup). The operating quantity depends on how test currents are injected into the relay (single-phase injection:
; three-phase pure zero-sequence injection:
).
Figure 5–55: NEUTRAL IOC1 SCHEME LOGIC
NEUTRAL IOC1
NEUTRAL IOC1
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
NEUTRAL IOC1 SIGNAL
SOURCE: SRC 1
Range: SRC 1, SRC 2
MESSAGE
NEUTRAL IOC1
PICKUP: 1.000
pu
Range: 0.000 to 30.000 pu in steps of 0.001
MESSAGE
NEUTRAL IOC1 PICKUP
DELAY: 0.00
s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NEUTRAL IOC1 RESET
DELAY: 0.00
s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NEUTRAL IOC1 BLOCK:
Off
Range: FlexLogic™ operand
MESSAGE
NEUTRAL IOC1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
NEUTRAL IOC1
EVENTS: Disabled
Range: Disabled, Enabled
I
op
3
I_0
K
I_1
⋅
–
(
)
×
=
where
K
1 16
⁄
=
I
op
0.9375
I
injected
⋅
=
I
op
3
I
injected
×
=
FLEXLOGIC OPERANDS
NEUTRAL IOC1 FUNCTION:
NEUTRAL IOC1 PICKUP:
NEUTRAL IOC1 SOURCE:
NEUTRAL IOC1 BLOCK:
NEUTRAL IOC1 DPO
NEUTRAL IOC1 OP
NEUTRAL IOC1 PKP
RUN
AND
827035A4.CDR
SETTING
SETTING
Enabled=1
Disabled=0
SETTING
SETTING
I
_0
Off=0
SETTINGS
NEUTRAL IOC1
RESET DELAY :
NEUTRAL IOC1
PICKUP DELAY :
t
PKP
t
RST
3( _0 - K _1 ) PICKUP
I
I
Summary of Contents for F60 UR Series
Page 2: ......
Page 4: ......
Page 30: ...1 20 F60 Feeder Protection System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 48: ...2 18 F60 Feeder Protection System GE Multilin 2 2 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2 ...
Page 126: ...4 30 F60 Feeder Protection System GE Multilin 4 2 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Page 354: ...5 228 F60 Feeder Protection System GE Multilin 5 9 TESTING 5 SETTINGS 5 ...
Page 382: ...6 28 F60 Feeder Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Page 398: ...8 8 F60 Feeder Protection System GE Multilin 8 2 FAULT LOCATOR 8 THEORY OF OPERATION 8 ...
Page 414: ...A 14 F60 Feeder Protection System GE Multilin A 1 PARAMETER LIST APPENDIXA A ...
Page 492: ...B 78 F60 Feeder Protection System GE Multilin B 4 MEMORY MAPPING APPENDIXB B ...
Page 530: ...D 10 F60 Feeder Protection System GE Multilin D 1 IEC 60870 5 104 APPENDIXD D ...
Page 542: ...E 12 F60 Feeder Protection System GE Multilin E 2 DNP POINT LISTS APPENDIXE E ...
Page 558: ...x F60 Feeder Protection System GE Multilin INDEX ...