ABB REL650 Product Manual page 18

Line distance protection REL650 ANSI
Product version: 1.3
Faulty phase identification with load encroachment FMPSPDIS
(21)
The phase selection function is design to accurately select the
proper fault loop(s) in the distance function dependent on the fault
type.
The heavy load transfer that is common in many transmission
networks may in some cases interfere with the distance
protection zone reach and cause unwanted operation. Therefore
the function has a built in algorithm for load encroachment.
The output signals from the phase selection function produce
important information about faulty phase(s), which can be used
for fault analysis as well.
Phase selection, quadrilateral characteristic with fixed angle
FDPSPDIS (21)
The operation of transmission networks today is in many cases
close to the stability limit. Due to environmental considerations,
the rate of expansion and reinforcement of the power system is
reduced, for example, difficulties to get permission to build new
power lines. Phase selection, quadrilateral characteristic with
fixed angle FDPSPDIS (21) is designed to accurately select the
proper faulted loop(s) in the distance function based on the fault
type.
The heavy load transfer that is common in many transmission
networks may make fault resistance coverage difficult to achieve.
Therefore, FDPSPDIS (21) has a built-in algorithm for load
encroachment, which gives the possibility to enlarge the resistive
setting of both the phase selection and the measuring zones
without interfering with the load.
The extensive output signals from the phase selection gives also
important information about faulty phase(s), which can be used
for fault analysis.
Directional impedance quadrilateral and mho ZDNRDIR (21D)
The evaluation of the direction to the fault is made in the
directional element ZDNRDIR (21D) for the quadrilateral and mho
characteristic distance protections ZQMPDIS (21).
Additional distance protection directional function for earth fault
ZDARDIR (21)
The evaluation of the direction to the fault is made by sequence
components in the additional directional element ZDARDIR (21) to
cover for high resistive faults during high load transfer. ZDARDIR
(21) shall be added by configuration to ZDNRDIR (21D).
Phase preference logic PPLPHIZ
Phase preference logic function PPLPHIZ is intended to be used
in isolated or high impedance grounded networks where there is a
requirement to trip only one of the faulty lines at cross-country
fault.
18
Phase preference logic inhibits tripping for single phase-to-
ground faults in isolated and high impedance grounded networks,
where such faults are not to be cleared by distance protection.
For cross-country faults, the logic selects either the leading or the
lagging phase-ground loop for measurement and initiates tripping
of the preferred fault based on the selected phase preference. A
number of different phase preference combinations are available
for selection.
Power swing detection ZMRPSB (68)
Power swings may occur after disconnection of heavy loads,
upon severe fault clearing or after tripping of big generation
plants.
Power swing detection function ZMRPSB (68) is used to detect
power swings and initiate block of all distance protection zones.
Occurrence of ground-fault currents during a power swing inhibits
the ZMRPSB (68) function to allow fault clearance.
Automatic switch onto fault logic, voltage and current based
ZCVPSOF
Automatic switch onto fault logic, voltage and current based
ZCVPSOF is a function that gives an instantaneous trip at closing
of breaker onto a fault. A dead line detection check is provided to
activate the function when the line is dead.
Mho distance protections can not operate for switch onto fault
condition when the phase voltages are close to zero. An
additional logic based on VI Level shall be configured for this
purpose.
5. Current protection
Instantaneous phase overcurrent protection, 3-phase output
PHPIOC (50)
The instantaneous three phase overcurrent function has a low
transient overreach and short tripping time to allow use as a high
set short-circuit protection function.
Instantaneous phase overcurrent protection, phase segregated
output SPTPIOC (50)
The instantaneous phase overcurrent function for single pole
tripping has a low transient overreach and short tripping time to
allow use as a high set short-circuit protection function and where
the requirement for tripping is one- and/or three-phase.
Four step phase overcurrent protection, 3-phase output
OC4PTOC (51/67)
The four step phase overcurrent protection function OC4PTOC
(51/67) has independent inverse time delay settings for step 1 and
4. Step 2 and 3 are always definite time delayed.
All IEC and ANSI inverse time characteristics are available.
1MRK 506 337-BUS B
ABB