GE L60 Instruction Manual page 519

9 THEORY OF OPERATION
OPERAND
PHASE SELECT AG
PHASE SELECT BG
PHASE SELECT CG
PHASE SELECT AB
PHASE SELECT BC
PHASE SELECT CA
PHASE SELECT ABG
PHASE SELECT BCG
PHASE SELECT CAG
If none of the fault types indicated above is determined, then three-phase fault conditions are checked to detect the pres-
ence of positive-sequence current and the absence of both zero-sequence and negative-sequence current. If these condi-
tions are met, then the
PHASE SELECT 3P
asserted, indicating that the phase selector failed to identify the fault type.
Finally, the states of the following additional FlexLogic operands are determined.
OPERAND
PHASE SELECT SLG
PHASE SELECT MULTI-P
The phase selector operands are reset ½ cycle after the
disturbance detector (50DD) initially operated. In the reset state, all phase selector FlexLogic operands are reset until reset
conditions are removed and the phase selector is ready for the next operation.
FLEXLOGIC OPERAND
OPEN POLE OP
FLEXLOGIC OPERAND
SRCn 50DD OP
FLEXLOGIC OPERAND
SRCn VT FUSE FAIL OP
SETTING
DISTANCE SOURCE:
I_0
I_1
I_2
V_0
V_1
V_2
GE Multilin
DESCRIPTION
Asserted when a phase A to ground fault is detected.
Asserted when a phase B to ground fault is detected.
Asserted when a phase C to ground fault is detected.
Asserted when a phase A to B fault is detected.
Asserted when a phase B to C fault is detected.
Asserted when a phase C to A fault is detected.
Asserted when a phase A to B to ground fault is detected.
Asserted when a phase B to C to ground fault is detected.
Asserted when a phase C to A to ground fault is detected.
FlexLogic operand is asserted; otherwise, the
DESCRIPTION
Asserted if any of PHASE SELECT AG, PHASE SELECT BG, or PHASE SELECT CG
operands is active.
Asserted if neither the PHASE SELECT SLG nor PHASE SELECT VOID operands are being
asserted.
OPEN POLE OP
DELAY
0.5 cycles
DELAY
DELAY
0
4 cycles
0
AND
Figure 9–30: PHASE SELECTOR LOGIC
L60 Line Phase Comparison System
9.2 SINGLE-POLE TRIPPING
PHASE SELECT VOID
FlexLogic operand is asserted or 500 ms after the
RESET
0
FLEXLOGIC OPERANDS
PHASE SELECT AG
START
500 ms
PHASE SELECT BG
PHASE SELECT CG
PHASE SELECT AB
PHASE SELECT BC
PHASE SELECT CA
PHASE SELECT ABG
PHASE SELECT BCG
PHASE SELECT CAG
PHASE SELECT 3P
PHASE SELECT SLG
PHASE SELECT MULTI-P
PHASE SELECT VOID
operand is
837027A5.CDR
9
9-37