GE D30 Instruction Manual page 472

SERIES COMPENSATED LINES
9
9-20
Figure 9-8: Dynamic reach for internal and external faults
LOW-CURRENT EXTERNAL
(a)
X
Set reach
HIGH-CURRENT EXTERNAL
(b)
X
Set reach
HIGH-CURRENT INTERNAL
(c)
X
Set reach
CHAPTER 9: THEORY OF OPERATION
FAULT
Impedance
Trajectory
Steady-state
apparent
impedance
The reach is safely
reduced
R
FAULT
Impedance
Trajectory (no
subsynchronous
oscillations)
Steady-state
apparent
impedance
The reach is not
reduced
R
FAULT
Impedance
Trajectory (no
subsynchronous
oscillations)
Steady-state
apparent
impedance
The reach is not
reduced
R
837730A1.CDR
D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL