5-182
L30 Line Current Differential System
GE Multilin
5.6 GROUPED ELEMENTS
5 SETTINGS
5
5.6.10 SUPERVISING ELEMENTS
a) MAIN MENU
PATH: SETTINGS
GROUPED ELEMENTS
SETTING GROUP 1(6)
SUPERVISING ELEMENTS
b) DISTURBANCE DETECTOR
PATH: SETTINGS
GROUPED ELEMENTS
SETTING GROUP 1(6)
SUPERVISING ELEMENTS
DISTURBANCE DETECTOR
The disturbance detector (50DD) element is an 87L-dedicated sensitive current disturbance detector that is used to detect
any disturbance on the protected system. This detector is intended for such functions as trip output supervision and starting
oscillography The disturbance detector also signals the 87L function that a disturbance (possible fault) occurred and to
resize the operating window to remove the pre-fault current. It is essential to have the disturbance detector enabled for
applications where the 87L operating time is critical.
If the disturbance detector is used to supervise the operation of the 87L function, it is recommended that the 87L trip ele-
ment be used. The
50DD SV
disturbance detector FlexLogic operand must then be assigned to an
87L TRIP SUPV
setting.
The disturbance detector function measures the magnitude of the negative-sequence current (I_2), the magnitude of the
zero-sequence current (I_0), the change in negative-sequence current (
I_2), the change in zero-sequence current (
I_0),
and the change in positive-sequence current (
I_1). The disturbance detector element uses net local current, computed as
a sum of all sources configured in the current differential element, to detect system disturbances.
The adaptive level detector operates as follows:
•
When the absolute level increases above 0.12 pu for I_0 or I_2, the adaptive level detector output is active and the
next highest threshold level is increased 8 cycles later from 0.12 to 0.24 pu in steps of 0.02 pu. If the level exceeds
0.24 pu, the current adaptive level detector setting remains at 0.24 pu and the output remains active (as well as the
disturbance detector output) when the measured value remains above the current setting.
•
When the absolute level is decreasing from in range from 0.24 to 0.12 pu, the lower level is set every 8 cycles without
the adaptive level detector active. Note that the 50DD output remains inactive during this change as long as the delta
change is less than 0.04 pu.
The delta level detectors (
I) detectors are designed to pickup for the 0.04 pu change in I_1, I_2, and I_0 currents. The
I
value is measured by comparing the present value to the value calculated 4 cycles earlier.
•
DD FUNCTION:
This setting is used to enable/disable the operation of the disturbance detector.
•
DD NON-CURRENT SUPV
: This setting is used to select a FlexLogic operand which will activate the output of the dis-
turbance detector upon events (such as frequency or voltage change) not accompanied by a current change.
•
DD CONTROL LOGIC
: This setting is used to prevent operation of I_0 and I_2 logic of disturbance detector during
conditions such as single breaker pole being open which leads to unbalanced load current in single-pole tripping
schemes. Breaker auxiliary contact can be used for such scheme.
SUPERVISING
ELEMENTS
DISTURBANCE
DETECTOR
DISTURBANCE
DETECTOR
DD
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
DD NON-CURRENT SUPV:
Off
Range: FlexLogic operand
MESSAGE
DD CONTROL LOGIC:
Off
Range: FlexLogic operand
MESSAGE
DD LOGIC SEAL-IN:
Off
Range: FlexLogic operand
MESSAGE
DD
EVENTS: Disabled
Range: Disabled, Enabled
Summary of Contents for L30
Page 10: ...x L30 Line Current Differential System GE Multilin TABLE OF CONTENTS ...
Page 30: ...1 20 L30 Line Current Differential System GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1 ...
Page 370: ...5 244 L30 Line Current Differential System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 464: ...A 10 L30 Line Current Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 600: ...C 30 L30 Line Current Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 610: ...D 10 L30 Line Current Differential System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Page 622: ...E 12 L30 Line Current Differential System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...
Page 634: ...F 12 L30 Line Current Differential System GE Multilin F 3 WARRANTY APPENDIX F F ...
Page 644: ...x L30 Line Current Differential System GE Multilin INDEX ...