GE T35 UR Series

GE Multilin T35 Transformer Protection System 5-135
5 SETTINGS 5.6 GROUPED ELEMENTS
5
c) INSTANTANEOUS DIFFERENTIAL
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  TRANSFORMER  INSTANTANEOUS DIFFERENTIAL
The instantaneous differential element acts as an instantaneous overcurrent element responding to the measured differen-
tial current magnitude (filtered fundamental frequency component) and applying a user-selectable pickup threshold. The
pickup threshold should be set greater than the maximum spurious differential current that could be encountered under
non-internal fault conditions (typically magnetizing inrush current or an external fault with extremely severe CT saturation).
Figure 5–48: INSTANTANEOUS DIFFERENTIAL SCHEME LOGIC
 INSTANTANEOUS
 DIFFERENTIAL
INST DIFFERENTIAL
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
INST DIFFERENTIAL
PICKUP: 8.000 pu
Range: 2.000 to 30.000 pu in steps of 0.001
MESSAGE
INST DIFF BLOCK:
Off
Range: FlexLogic operand
MESSAGE
INST DIFFERENTIAL
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
INST DIFFERENTIAL
EVENTS: Disabled
Range: Disabled, Enabled
SETTING
ACTUAL VALUE
SETTING
SETTING
FLEXLOGIC OPERAND
FLEXLOGIC OPERANDS
INST DIFFERENTIAL
FUNCTION:
DIFF PHASOR
INST DIFF BLOCK:
INST DIFFERENTIAL
PICKUP:
XFMR INST DIFF OP
XFMR INST DIFF OP C
XFMR INST DIFF OP B
XFMR INST DIFF OP A
Off=0
Enabled=1
Disabled=0
AND
828000A1.CDR
RUN
RUN
RUN
Iad > PICKUP
Iad
Ibd
Icd
Ibd > PICKUP
Icd > PICKUP
OR