GE D90 Plus Instruction Manual page 669

CHAPTER 15: THEORY OF OPERATION
Two-bit channels
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Table 33: Unblocking scheme trip table for single-bit channels
Remote data
Bit pattern
RX1 LOG1
0 or 1 1
0 or 1 1
0 or 1 1
0 or 1 1
The scheme initiates a three-phase trip if the phase selector fails to recognize the fault
type or after the
AR FORCE 3P TRIP
Two-bit communication channels for pilot-aided schemes use the RX1, RX2, TX1, and TX2
operands for each scheme. The tables show how the fault data is coded.
Table 34: Permissive scheme transmit codes for two-bit channels
Phase selector determination of fault type
AG, BC, or BCG
BG, CA, or CAG
CG, AB, ABG, 3P, or unrecognized
Table 35: Blocking scheme transmit codes for two-bit channels
Phase selector determination of fault
type
AG, BC, or BCG
BG, CA, or CAG
CG, AB, ABG, 3P, or unrecognized
Table 36: Unblocking scheme transmit codes for two-bit channels
Phase selector determination of fault type
AG, BC, or BCG
BG, CA, or CAG
CG, AB, ABG, 3P, or unrecognized
Table 37: Permissive scheme trip table for two-bit channels
Remote data
Bit pattern Remote determination of
fault type
RX1 RX2
1 0 AG, BC, or BCG
0 1 BG, CA, or CAG
1 1 CG, AB, ABG, 3P, or
unrecognized
0 1 BG, CA, or CAG
1 1 CG, AB, ABG, 3P, or
unrecognized
Local data
Remote determination Local determination of
of fault type fault type
Any AG fault
Any BG fault
Any CG fault
Any ABG, BCG, CAG, AB, BC,
CA, or 3P fault, or
unrecognized
operand is asserted.
Bit pattern
TX1
1
0
1
Bit pattern
TX1 TX2
0 1
1 0
0 0
Bit pattern
TX1
1
0
1
Local data
Local determination of fault
type
AG, AB, ABG, CA, CAG, or 3P
AG
AG
BG, AB, ABG, BC, BCG, or 3P
BG
SINGLE-POLE TRIPPING
Trip output
DCUB TRIP A
DCUB TRIP B
DCUB TRIP C
DCUB TRIP 3P
TX2
0
1
1
Operands asserted
TX1 STOP TX2 STOP
1 0
0 1
1 1
TX2
0
1
1
Trip output
TRIP PHASE A
TRIP PHASE A
TRIP PHASE A
TRIP PHASE B
TRIP PHASE B
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