CHAPTER 15: THEORY OF OPERATION
SINGLE-POLE TRIPPING
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
659
Table 33: Unblocking scheme trip table for single-bit channels
The scheme initiates a three-phase trip if the phase selector fails to recognize the fault
type or after the
AR FORCE 3P TRIP
operand is asserted.
Two-bit channels
Two-bit communication channels for pilot-aided schemes use the RX1, RX2, TX1, and TX2
operands for each scheme. The fault data is coded as shown in the following tables.
Table 34: Permissive scheme transmit codes for two-bit channels
Table 35: Blocking scheme transmit codes for two-bit channels
Table 36: Unblocking scheme transmit codes for two-bit channels
Table 37: Permissive scheme trip table for two-bit channels
Remote data
Local data
Bit pattern
Remote determination
of fault type
Local determination of
fault type
Trip output
RX1
LOG1
0 or 1
1
Any
AG fault
DCUB TRIP A
0 or 1
1
Any
BG fault
DCUB TRIP B
0 or 1
1
Any
CG fault
DCUB TRIP C
0 or 1
1
Any
ABG, BCG, CAG, AB, BC,
CA, or 3P fault, or
unrecognized
DCUB TRIP 3P
Phase selector determination of fault type
Bit pattern
TX1
TX2
AG, BC, or BCG
1
0
BG, CA, or CAG
0
1
CG, AB, ABG, 3P, or unrecognized
1
1
Phase selector determination of fault
type
Bit pattern
Operands asserted
TX1
TX2
TX1 STOP
TX2 STOP
AG, BC, or BCG
0
1
1
0
BG, CA, or CAG
1
0
0
1
CG, AB, ABG, 3P, or unrecognized
0
0
1
1
Phase selector determination of fault type
Bit pattern
TX1
TX2
AG, BC, or BCG
1
0
BG, CA, or CAG
0
1
CG, AB, ABG, 3P, or unrecognized
1
1
Remote data
Local data
Bit pattern
Remote determination of
fault type
Local determination of fault
type
Trip output
RX1
RX2
1
0
AG, BC, or BCG
AG, AB, ABG, CA, CAG, or 3P
TRIP PHASE A
0
1
BG, CA, or CAG
AG
TRIP PHASE A
1
1
CG, AB, ABG, 3P, or
unrecognized
AG
TRIP PHASE A
0
1
BG, CA, or CAG
BG, AB, ABG, BC, BCG, or 3P
TRIP PHASE B
1
1
CG, AB, ABG, 3P, or
unrecognized
BG
TRIP PHASE B