GE L30 Instruction Manual page 313

5 SETTINGS
• DD LOGIC SEAL-IN: This setting is used to maintain disturbance detector output for such conditions as balanced
three-phase fault, low level time overcurrent fault, etc. whenever the disturbance detector might reset. Output of the
disturbance detector will be maintained until the chosen FlexLogic™ operand resets.
The user may disable the
bance on the system which may result in filling the events buffer and possible loss of valuable data.
NOTE
SETTING
DD FUNCTION:
Enabled=1
Disabled=0
ACTUAL
COMPUTE SEQ.
CURRENTS
I_1
I_2
I_0
SETTING
DD CONTROL
LOGIC:
Off=0
SETTING
DD LOGIC
SEAL-IN:
Off=0
SETTING
DD NON-CURRENT
SUPV:
Off=0
GE Multilin
setting as the disturbance detector element will respond to any current distur-
DD EVENTS
LOGIC
DELTA LEVEL
DETECTOR
RUN
ABS (I_1-I_1')>0.04 pu
(I_1' is 4 cycles old)
ABS (I_2-I_2')>0.04 pu
(I_2' is 4 cycles old)
ABS (I_0-I_0')>0.04 pu
(I_0' is 4 cycles old)
LOGIC
ADAPTIVE LEVEL
DETECTOR
RUN
AND
I_0 > 0.12 to 0.24 pu
I_2 > 0.12 to 0.24 pu
NOTE:
ADJUSTMENTS ARE
MADE ONCE EVERY
8 CYCLES TO THE
NEXT LEVEL (HIGHER
OR LOWER) IN 0.02 pu
STEPS USING THE
HIGHEST VALUE OF
I_0 AND I_2.
AND
AND
Figure 5–77: DISTURBANCE DETECTOR SCHEME LOGIC
L30 Line Current Differential System
5.6 GROUPED ELEMENTS
OR
OR
OR
FLEXLOGIC OPERAND
50DD SV
OR
5
827044A6.CDR
5-169