5 SETTINGS
a) COMMON DISTANCE SETTINGS
PATH: SETTINGS
GROUPED ELEMENTS
DISTANCE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
The
identifies the signal source for all distance functions. The mho distance functions use a dynamic
DISTANCE SOURCE
characteristic: the positive-sequence voltage – either memorized or actual – is used as a polarizing signal. The memory
voltage is also used by the built-in directional supervising functions applied for both the mho and quad characteristics.
The
setting specifies the length of time a memorized positive-sequence voltage should be used in the
MEMORY DURATION
distance calculations. After this interval expires, the relay checks the magnitude of the actual positive-sequence voltage. If
it is higher than 10% of the nominal, the actual voltage is used, if lower – the memory voltage continues to be used.
The memory is established when the positive-sequence voltage stays above 80% of its nominal value for five power system
cycles. For this reason it is important to ensure that the nominal secondary voltage of the VT is entered correctly under the
SETTINGS
SYSTEM SETUP
Set
long enough to ensure stability on close-in reverse three-phase faults. For this purpose, the maxi-
MEMORY DURATION
mum fault clearing time (breaker fail time) in the substation should be considered. On the other hand, the
cannot be too long as the power system may experience power swing conditions rotating the voltage and current
TION
phasors slowly while the memory voltage is static, as frozen at the beginning of the fault. Keeping the memory in effect for
too long may eventually lead to incorrect operation of the distance functions.
GE Multilin
SETTING GROUP 1(6)
DISTANCE
SOURCE: SRC 1
MEMORY
DURATION: 10 cycles
FORCE SELF-POLAR:
Off
FORCE MEM-POLAR:
Off
PHASE DISTANCE Z1
PHASE DISTANCE Z2
PHASE DISTANCE Z3
PHASE DISTANCE Z4
PHASE DISTANCE Z5
GROUND DISTANCE Z1
GROUND DISTANCE Z2
GROUND DISTANCE Z3
GROUND DISTANCE Z4
GROUND DISTANCE Z5
AC INPUTS
VOLTAGE BANK
T60 Transformer Protection System
DISTANCE
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
Range: 5 to 25 cycles in steps of 1
Range: FlexLogic operand
Range: FlexLogic operand
See page 5–182.
See page 5–182.
See page 5–182.
See page 5–182.
See page 5–182.
See page 5–192.
See page 5–192.
See page 5–192.
See page 5–192.
See page 5–192.
menu.
5.6 GROUPED ELEMENTS
5.6.3 DISTANCE
MEMORY DURA-
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