8-22
D60 Line Distance Protection System
GE Multilin
8.5 SINGLE-POLE TRIPPING
8 THEORY OF OPERATION
8
•
Notify the phase selector when a trip operation is imminent.
When notified that a single pole operation has been initiated open pole detector will:
•
Initiate blocking of protection elements that could potentially maloperate when a breaker pole is open.
•
Instruct the phase selector to de-assert all outputs, as an open pole invalidates calculations.
The operation of the scheme on a line in a single breaker arrangement will be described. The line is protected by a D60
relay using the line pickup and zone 1 phase and ground distance elements, and a permissive overreaching transfer trip
scheme (using zone 2 phase and ground distance elements as well as negative-sequence directional overcurrent ele-
ments,
GND DIR O/C FWD:
“
NEG SEQ OC1 FWD
”,
GND DIR O/C REV:
“
NEG SEQ OC1 REV
”). Zone 1 is configured to issue a sin-
gle-pole trip when appropriate (
TRIP 1-POLE INPUT-1:
“
GND DIST Z1 OP
”,
TRIP 1-POLE INPUT-2:
“
PHS DIST Z1 OP
”). By default
the POTT scheme will issue a single-pole trip. It is assumed that when tripping three-poles both the zone 1 and the POTT
shall initiate three-pole reclosing. This is achieved by setting
TRIP RECLOSE INPUT-1:
“
POTT TRIP 3P
”,
TRIP RECLOSE INPUT-2:
“
GND DIST Z1 OP
”, and
TRIP RECLOSE INPUT-3:
“
PHS DIST Z1 OP
”.
It is assumed for this discussion that the relay features that are shown on
Single pole operation
diagram above have all
been programmed for the application and are in service. The description begins with line breakers open at both the local
and remote ends, and the operation of the scheme is described in chronological order.
Because the line is de-energized the line pickup element is armed. The recloser is presently enabled. An operator requests
that breaker control close the breaker, and it operates output relays to close breaker poles A, B and C. This operator man-
ual close request is also forwarded from breaker control to recloser, which becomes disabled, de-asserting its “Enabled”
output. This output is transferred to trip output, where it converts any input request for a single pole operation into a three-
pole operation. At the recloser, the
AR1 BLK TIME @ MAN CLOSE
timer is started.
The breaker closes and status monitoring contacts on the breaker poles change state; the new breaker pole states are
reported to breaker control, which in turn transfers these states to the recloser, trip output, breaker failure and open pole
detector. Because a fault is not detected the
AR1 BLK TIME @ MAN CLOSE
times out and the recloser is enabled, which
asserts the “Enabled” output, informing the trip output element that single pole trip operations are now permitted. When nor-
mal voltage appears on the line the line pickup element is disarmed. As the local line breaker has not tripped the operator
closes the breaker at the remote end of the line, placing the line in service.
Several scenarios are considered below.
b) SLG FAULT
An AG fault occurs close to the considered relay. Immediately after the fault, the disturbance detector (50DD) picks-up and
activates the phase selector. The phase selector recognizes an AG fault by asserting its
PHASE SELECT AG
operand.
Ground distance zone 1 (AG element) responds to the fault. As the fault is close to the relay, phase distance zone 1 (AB,
CA elements) may respond to this fault as well. In any case, a single-pole operation is requested by zone 1 via the
GND
DIST Z1 OP
and/or
PHS DIST Z1 OP
operands.
At this moment the request to trip is placed for the trip output. As the fault is recognized as an AG fault, the TRIP PHASE A
operand is asserted by the trip output. This signal is passed to the breaker control scheme and results in tripping pole A of
the breaker.
Simultaneously with the
TRIP PHASE A
operand, the
TRIP 1-POLE
operand is asserted. This operand activates the open pole
detector. The latter detector responds to the
TRIP PHASE A
signal by declaring phase A open by asserting
OPEN POLE OP
A
(even before it is actually opened). The
TRIP PHASE A
signal resets only after the breaker actually operates as indicated
by its auxiliary contact. At this moment the open pole detector responds to the breaker position and continues to indicate
phase A opened. This indication results in establishing blocking signals for distance elements (
OPEN POLE BLK AB
,
OPEN
POLE BLK CA
operands are asserted). If neutral and negative-sequence overcurrent elements are mapped into the trip out-
put to trigger single-pole tripping, they must be blocked with the
OPEN POLE BLK N
operand, specifically provided for this
purpose. The
OPEN POLE BLK N
operand must be assigned through the block setting of the overcurrent element. The two
latter operands block phase distance AB and CA elements, respectively (all zones); the
OPEN POLE
A OP
blocks the
ground distance AG elements (all zones). As a result, the Z1 OP and Z2 PKP operands that were picked-up reset immedi-
ately. The following distance elements remain operational guarding the line against evolving faults: BG, CG and BC.
As zone 2 and/or negative-sequence directional elements pick up due to the fault, the permission to trip is keyed to the
remote end. Assume here that a single-bit channel is used. If so, no extra information is sent to the remote end, just permis-
sion to trip sent over the TX1 operand. Upon receiving permission to trip over RX1, the POTT scheme decides to trip. The
scheme will check the phase selector for phase type identification and will issue a trip for phase A by asserting the
POTT
TRIP A
operand. This operand is passed to the trip output and results in exactly same action as described above for zone 1.
Содержание D60
Страница 61: ...GE Multilin D60 Line Distance Protection System 2 31 2 PRODUCT DESCRIPTION 2 3 SPECIFICATIONS 2 ...
Страница 62: ...2 32 D60 Line Distance Protection System GE Multilin 2 3 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2 ...
Страница 102: ...3 40 D60 Line Distance Protection System GE Multilin 3 3 DIRECT INPUT AND OUTPUT COMMUNICATIONS 3 HARDWARE 3 ...
Страница 134: ...4 32 D60 Line Distance Protection System GE Multilin 4 3 FACEPLATE INTERFACE 4 HUMAN INTERFACES 4 ...
Страница 508: ...5 374 D60 Line Distance Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Страница 538: ...6 30 D60 Line Distance Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Страница 610: ...10 8 D60 Line Distance Protection System GE Multilin 10 2 BATTERIES 10 MAINTENANCE 10 ...
Страница 622: ...A 12 D60 Line Distance Protection System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Страница 745: ...GE Multilin D60 Line Distance Protection System B 123 APPENDIX B B 4 MEMORY MAPPING B ...
Страница 746: ...B 124 D60 Line Distance Protection System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Страница 776: ...C 30 D60 Line Distance Protection System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Страница 792: ...E 10 D60 Line Distance Protection System GE Multilin E 1 IEC 60870 5 104 PROTOCOL APPENDIX E E ...
Страница 804: ...F 12 D60 Line Distance Protection System GE Multilin F 2 DNP POINT LISTS APPENDIX F F ...
Страница 826: ...xii D60 Line Distance Protection System GE Multilin INDEX ...