ABB RELION 670 Series Product Manual page 29

Transformer protection RET670 2.1 IEC
X
Reverse
operation
IEC05000034 V1 EN-US
Figure 11. Typical quadrilateral distance protection zone with
Phase selection, quadrilateral characteristic with
settable angle function FRPSPDIS activated
The independent measurement of impedance for each
fault loop together with a sensitive and reliable built in
phase selection makes the function suitable in
applications with single phase auto-reclosing.
The distance protection zones can operate, independent
of each other, in directional (forward or reverse) or non-
directional mode. This makes them suitable, together
with different communication schemes, for the
protection of power lines and cables in complex network
configurations, such as parallel lines, multi-terminal
lines.
Directional impedance element for Mho
characteristic ZDMRDIR
The phase-to-earth impedance elements can be
optionally supervised by a phase unselective directional
function (phase unselective, because it is based on
symmetrical components).
Mho impedance supervision logic ZSMGAPC
The Mho impedance supervision logic (ZSMGAPC)
includes features for fault inception detection and high
SIR detection. It also includes the functionality for loss
of potential logic as well as for the pilot channel
blocking scheme.
ZSMGAPC can mainly be decomposed in two different
parts:
1. A fault inception detection logic
2. High SIR detection logic
Faulty phase identification with load encroachment
FMPSPDIS
ABB
Forward
operation
R
en05000034.vsd
The ability to accurately and reliably classify different
types of fault so that single phase tripping and
autoreclosing can be used plays an important roll in
today's power systems.
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, which gives the
possibility to enlarge the resistive setting of the
measuring zones without interfering with the load.
The output signals from the phase selection function
produce important information about faulty phase(s),
which can be used for fault analysis as well.
Distance protection zone, quadrilateral
characteristic, separate settings ZMRPDIS,
ZMRAPDIS
The line distance protection is up to five zone full
scheme protection with three fault loops for phase-to-
phase faults and three fault loops for phase-to-earth
fault for each of the independent zones. Individual
settings for each zone in resistive and reactive reach
gives flexibility for use as back-up protection for
transformer connected to overhead lines and cables of
different types and lengths.
Mho alternative quadrilateral characteristic is available.
ZMRPDIS together with Phase selection, quadrilateral
characteristic with settable angle FRPSPDIS has
functionality for load encroachment, which increases the
SEMOD175532-4 v2
possibility to detect high resistive faults on heavily
loaded lines.
The distance protection zones can operate, independent
of each other, in directional (forward or reverse) or non-
directional mode.
SEMOD153843-5 v3
Phase selection, quadrilateral characteristic with
settable angle FRPSPDIS
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. The ability to accurately and reliably classify
the different types of fault, so that single pole tripping
and autoreclosing can be used plays an important role in
this matter. The phase selection function is designed to
accurately select the proper fault loop in the distance
function dependent on the fault type.
1MRK 504 155-BEN F
SEMOD153825-5 v7
GUID-014501E7-EE0D-440F-8DC8-C44B848E49D3 v2
GUID-09D0E480-C003-424E-BECD-A82BCB0052CD v1
29