GE Entellisys 4.0, Инструкция по применению

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grounded systems. A ground fault that sends a grounded systems. A ground fault that sends a
feeder below a MSGF zone into ground-fault timing
feeder below a MSGF zone into ground-fault timing
increments the delay of the MSGF zone by 100ms,
increments the delay of the MSGF zone by 100ms,
which means all the circuit breakers feeding into the
which means all the circuit breakers feeding into the
zone (mains and ties) are timed similarly. See the
zone (mains and ties) are timed similarly. See the
description of multi-source ground-fault protection
description of multi-source ground-fault protection
for further details.
for further details.
In a single-ground system with no ground-fault In a single-ground system with no ground-fault
protection zones, the time delays are incremented
protection zones, the time delays are incremented
by 100ms per tier above the tier in which the fault
by 100ms per tier above the tier in which the fault
is sensed, in the same way as with short-time ZSI.
is sensed, in the same way as with short-time ZSI.
Zone-based overcurrent protection or bus-differential Zone-based overcurrent protection or bus-differential
protection (87B)
protection (87B)
Entellisys low-voltage switchgear can provide Entellisys low-voltage switchgear can provide
complete zone-based overcurrent protection (also
complete zone-based overcurrent protection (also
known as 87B protection in ANSI relay nomenclature).
known as 87B protection in ANSI relay nomenclature).
The minimum setting for pickup is 20% of the CT
The minimum setting for pickup is 20% of the CT
rating of the largest circuit breaker in the zone
rating of the largest circuit breaker in the zone
and the maximum setting is 22,000A. Any circuit
and the maximum setting is 22,000A. Any circuit
breaker feeding into a protected zone may be
breaker feeding into a protected zone may be
tripped in as little as 25ms.
tripped in as little as 25ms.
The complete Entellisys zone-based bus-protection The complete Entellisys zone-based bus-protection
system combines differential protection and zone-
system combines differential protection and zone-
selective
selective interlocking to interlocking to handle faults o handle faults over a wide ver a wide
range of magnitudes. This combination of two range of magnitudes. This combination of two
different methods for detecting faults allows
different methods for detecting faults allows
detection of small and large faults. Furthermore,
detection of small and large faults. Furthermore,
it is not affected by CT saturation issues. The
it is not affected by CT saturation issues. The
differential-protection algorithm may be set to pick
differential-protection algorithm may be set to pick
up
up as high as 22,00 as high as 22,000 amperes or as lo 0 amperes or as low as 800A w as 800A
in a zone with a 4000A main. in a zone with a 4000A main.
The algorithm is suspended if any one current in The algorithm is suspended if any one current in
or out of the zone exceeds ten times the CT rating
or out of the zone exceeds ten times the CT rating
for that circuit
for that circuit breaker breaker.. Zone-selective interlocking Zone-selective interlocking
then takes over protection of the zone and can then takes over protection of the zone and can
provide equally fast detection and tripping. Hence,
provide equally fast detection and tripping. Hence,
in a radial system substation with a 4000A main and
in a radial system substation with a 4000A main and
several 800A feeders, faults up to 39,999 amperes
several 800A feeders, faults up to 39,999 amperes
may be sensed by the bus-differential algorithm,
may be sensed by the bus-differential algorithm,
while faults of 40,000 amperes and above are
while faults of 40,000 amperes and above are
sensed by the short time and ZSI algorithms. For
sensed by the short time and ZSI algorithms. For
the smaller faults, the CPU trips the main circuit
the smaller faults, the CPU trips the main circuit
breaker at the set time delay for the bus-differential
breaker at the set time delay for the bus-differential
zone, while for the larger faults the CPU trips the
zone, while for the larger faults the CPU trips the
circuit breaker at a time delay set for the short-time
circuit breaker at a time delay set for the short-time
function of that main circuit breaker. Both of these
function of that main circuit breaker. Both of these
time bands may be as short as 25ms. In the case
time bands may be as short as 25ms. In the case
of a through fault in one of the 800A feeders, the of a through fault in one of the 800A feeders, the
bus-differential algorithm senses faults as high as
bus-differential algorithm senses faults as high as
7999A and keeps the main from tripping. For faults
7999A and keeps the main from tripping. For faults
of 8000A and above, the CPU adds a delay to the
of 8000A and above, the CPU adds a delay to the
main circuit breaker per the tier assignments for
main circuit breaker per the tier assignments for
the zone and trips the feeder circuit breaker at its
the zone and trips the feeder circuit breaker at its
set time delay, which may be as little as 25ms.
set time delay, which may be as little as 25ms.
Zone-based bus protection provides optimal pro- Zone-based bus protection provides optimal pro-
tection with no sacrifice in selectivity. GE’s unique
tection with no sacrifice in selectivity. GE’s unique
method uses a
method uses a straightforwar straightforward differential algorithm d differential algorithm
in combination with the Entellisys zone-selective in combination with the Entellisys zone-selective
interlocking to provide complete bus protection for
interlocking to provide complete bus protection for
faults from below rated current into a zone to the
faults from below rated current into a zone to the
full short circuit rating of the equipment, with no
full short circuit rating of the equipment, with no
concerns over CT saturation. Faults may be detected
concerns over CT saturation. Faults may be detected
and circuit breakers tripped as fast as 25ms. In
and circuit breakers tripped as fast as 25ms. In
addition, the Entellisys zone-protection system is
addition, the Entellisys zone-protection system is
able to defin
able to define backup bre e backup breakers akers to be tripped in to be tripped in
case the first circuit breakers do not clear the fault case the first circuit breakers do not clear the fault
and alarm levels that may be used if tripping for
and alarm levels that may be used if tripping for
low-level faults is not desired.
low-level faults is not desired.
How bus-differential protection works How bus-differential protection works
The Entellisys bus-differential algorithm is based on The Entellisys bus-differential algorithm is based on
zones defined via the HMI. All the circuit breakers
zones defined via the HMI. All the circuit breakers
connected to each zone should be identified.
connected to each zone should be identified.
The fol The followin lowing setti g settings are ngs are made at t made at the facto he factory ry for for
each zone: each zone:
•• Zone definition
Zone definition and member and member circuit circuit breaker breaker
identification identification
•• Current flow di Current flow direction for rection for each circuit each circuit breaker breaker
•• Prima Primary breaker ry breakers to be tripped for an in-z s to be tripped for an in-zone one
fault (p fault (primary rimary trip tar trip target) get)
•• Backup br Backup breakers to be tri eakers to be tripped for an in-z pped for an in-zone one
fault (secondary trip targets) fault (secondary trip targets)
These settings These settings are are recorded recorded and fixed when and fixed when the the
CPU is powered. If the settings are changed via the CPU is powered. If the settings are changed via the
HMI, the CPU must be rebooted. If invalid settings
HMI, the CPU must be rebooted. If invalid settings
are detected, the CPU deactivates the 87B function
are detected, the CPU deactivates the 87B function
and records an event.
and records an event.
Each bus-differential function has several settings Each bus-differential function has several settings
that may be individually user selected for each
that may be individually user selected for each
zone and each topology:
zone and each topology:
1.
1. Sel Select ect the the TRIP TRIP or O or OPEN PEN glo global bal set settin ting fo g forr
protection settings to choose whether protective protection settings to choose whether protective
functions will trip (includes lockout) or open
functions will trip (includes lockout) or open
(excludes lockout) the target circuit breakers.
(excludes lockout) the target circuit breakers.
Section 7. Protection Section 7. Protection