GE D90 Plus - Page 669

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 tables show how the fault data is coded.
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 0110
BG, CA, or CAG 1001
CG, AB, ABG, 3P, or unrecognized0011
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