GE L30

5-188 L30 Line Current Differential System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
Figure 5–75: NEGATIVE SEQUENCE TOC1 SCHEME LOGIC
b) NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT (ANSI 50Q, IEC PIOC)
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEGATIVE SEQUENCE CURRENT  NEG SEQ OC1(2)
The negative-sequence instantaneous overcurrent element may be used as an instantaneous function with no intentional
delay or as a definite time function. The element responds to the negative-sequence current fundamental frequency phasor
magnitude (calculated from the phase currents) and applies a positive-sequence restraint for better performance: a small
portion (12.5%) of the positive-sequence current magnitude is subtracted from the negative-sequence current magnitude
when forming the operating quantity:
(EQ 5.21)
The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious negative-sequence cur-
rents resulting from:
 NEG SEQ IOC1

NEG SEQ IOC1
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
NEG SEQ IOC1 SIGNAL
SOURCE: SRC 1
Range: SRC 1, SRC 2
MESSAGE
NEG SEQ IOC1
PICKUP: 1.000 pu
Range: 0.000 to 30.000 pu in steps of 0.001
MESSAGE
NEG SEQ IOC1 PICKUP
DELAY: 0.00 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NEG SEQ IOC1 RESET
DELAY: 0.00 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NEG SEQ IOC1 BLOCK:
Off
Range: FlexLogic operand
MESSAGE
NEG SEQ IOC1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
NEG SEQ IOC1
EVENTS: Disabled
Range: Disabled, Enabled
FLEXLOGIC OPERANDS
NEG SEQ TOC1 FUNCTION:
NEG SEQ TOC1 PICKUP:
NEG SEQ TOC1 CURVE:
NEG SEQ TOC1 TD MULTIPLIER:
NEG SEQ TOC1 RESET:
NEG SEQ TOC1 INPUT:
NEG SEQ TOC1 SOURCE:
NEG SEQ TOC1 BLOCK:
NEG SEQ TOC1 DPO
NEG SEQ TOC1 OP
NEG SEQ TOC1 PKP
AND
827057A5.CDR
SETTING
SETTING
Enabled=1
SETTING
SETTING
Neg Seq
Off=0
t
NEG SEQ PICKUP
<
RUN
I
op
I_2 K I_1 where K⋅– 18⁄==