Low-pressure compressor

bypass-air collector
• Used to vent air overboard thru the
LPC.
• Prevent LPC stall MARGINE
during start-up, partial power, and
large power transients.
• Has 12 doors, six actuators and two
actuators have linear variable
differential transformers.
• Part of compressor front frame
assembly.
Low-pressure compressor (LPC)
assembly
• LPC is a 5- stage compressor with a 5
stage fixed stator.
• Horizontally split.
• The engine has one probe each
that measures LPC inlet total
temperature (T2) and LPC inlet
total pressure (P2),both mounted
on the VIGV case.
• Compresses air by a ratio of 2.4 to 1.
• The LPC is also equipped with
two-eddy current-type speed
sensors (XN2A and XN2B) used
for measurement of the LPC rotor
speed (XN2).
 Variable inlet guide vane (VIGV)
assembly
• Air intake interface with a radial inlet duct.
• Two types inlet.
– Variable inlet guide vane.
– Stationary inlet vanes.
• Located in front of LPC.
• Inlet guide vanes have 43 blades or vanes.
• The VIGV system improves performance for both
simple cycle and heat-recovery cycles.
• It also helps minimize VBV flow and pressure
levels, thereby reducing associated flow noise.
 MAJOR COMPONENTS
• Variable inlet guide vane (VIGV) assembly
• Low-pressure compressor (LPC) assembly
• Low-pressure compressor bypass-air collector
• Low-pressure compressor front frame assembly
• High-pressure compressor (HPC) assembly
• Compressor rear frame assembly
• Combustor assembly
• High-pressure turbine assembly
• Low-pressure turbine assembly
• Turbine rear frame assembly
• Accessory gearbox
BEARINGS & SUMPS
• Eight anti-friction roller-
and ball-type bearings
support the rotating
components and the
aerodynamic loads in the
LM6000.
• By design, the bearings do
not generate significant
heat due to friction.
• They do, however, absorb
heat transmitted from the
engine’s hot-gas path and
because of this, lube oil is
supplied to the bearings
for cooling purposes.
The Roller bearings support radial loads and axial thrust
loads are supported by Ball bearings.
Labyrinth-type seals control the flow of air into the sump
areas to prevent excess oil consumption.
 LM6000 OVERVIEW
• An igniter initially ignites the fuel-air mixture and,
once combustion is self-sustaining, the igniter is
turned off.
• The hot gas that results from combustion is
directed into the HPT that drives the HPC.
• This gas further expands through the LPT, which
drives the LPC and the output load.
 LM6000 OVERVIEW
• Air leaving the LPC is directed into the HPC.
• Variable bypass valves (VBV's) are arranged in
the flow passage between the two compressors to
regulate the airflow entering the HPC at idle and at
low power.
• To further control the airflow, the HPC is equipped
with variable stator vanes (VSV's).
• The HPC compresses the air to a ratio of
approximately 12:1, resulting in a total
compression ratio of 30:1, relative to ambient.
• From the HPC, the air is directed into the annular
combustor section, where it mixes with the fuel
from the 30 fuel nozzles
 LM6000 OVERVIEW
• The high-pressure rotor consists of the 14-stage HPC
and the 2-stage HPT that drives it.
• The high-pressure (HP) core consists of the HPC, the
combustor, and the HPT.
• The high- and low-pressure turbines drive the high-
and low-pressure compressors through concentric
drive shafts.
• Air enters the gas turbine at the VIGV's and passes
into the LPC.
• The LPC compresses the air by a ratio of
approximately 2.4:1.
 LM6000 OVERVIEW
• The LM6000 gas turbine is a dual-rotor, concentric drive-
shaft gas turbine, capable of driving a load from the front
and/or rear of the low-pressure (LP) rotor.
• The main components consist of:
– Variable inlet guide vane (VIGV) assembly or inlet frame assembly,
– 5-stage low-pressure compressor (LPC),
– 14-stage variable-geometry high-pressure compressor (HPC),
– Annular combustor,
– 2-stage high-pressure turbine (HPT),
– 5-stage low-pressure turbine (LPT),
– Accessory gearbox (AGB) assembly, and accessories.
• The low-pressure (LP) rotor consists of the LPC and the
LPT that drive it.
 LM6000 OVERVIEW
• The General Electric LM 6000 gas turbine is a
stationary gas turbine that is derived from the
family of CF6jet engines.
• The aircraft version of the engine is called the
CF6-80C2 turbofan engine and is used to drive
several types of “wide body” commercial aircraft,
like the Boeing 747-400.
 AXIAL FLOW COMPRESSOR

• It compresses a large volume of low-pressure air at

low velocity into a small volume of high-velocity air
at high pressure.
• Output pressure is increased by divergence in
each static interstage section.
• Rotating compressor blades between each static
stage increases the velocity that is lost by injecting
energy.
 CONVERGENT AND DIVERGENT DUCTS

• Compressors in gas turbine engines use

convergent and divergent ducts to generate the
high pressures necessary to:
– (a) provide a “wall of pressure,” preventing expanding
hot gas from exiting through the engine inlet as well as
through the exhaust;
– (b) provide the proper ratio of air-to-fuel for efficient
combustion and cooling of the combustion chamber.
• Pressure decreases through convergent ducts and
increases through divergent ducts,
 GE LM 6000

DETAILS OF CONSTRUCTION
 FLAME-STABILIZING AND
GENERAL-FLOW PATTERNS
• The temperature of the flame illustrated in the
center of the combustor is approximately 3200° F
at its tip when the engine is operating at full load.
• Are Metals in combustion chamber construction
capable of withstanding temperatures in this
range?
• Air flowing into the inner chamber is directed
through small holes to shape the flame centering it
within the chamber, to prevent its contact with the
chamber walls.
• What % of airflow is used for Combustion and
Cooling/Flame Shaping?
 INLET GUIDE VANES
• Inlet guide vanes direct, or align, airflow into the
first rotating blade section where velocity is
increased by the addition of energy.
• The following stator vane section is divergent,
providing an increase in static pressure and a
decrease in air velocity.
• Each subsequent stage provides an incremental
increase in velocity and static pressure until the
desired level of pressure and velocity is reached.
 AXIAL FLOW COMPRESSOR

• It compresses a large volume of low-pressure air at

low velocity into a small volume of high-velocity air
at high pressure.
• Output pressure is increased by divergence in
each static interstage section.
• Rotating compressor blades between each static
stage increases the velocity that is lost by injecting
energy.
 CONVERGENT AND DIVERGENT DUCTS

• Compressors in gas turbine engines use

convergent and divergent ducts to generate the
high pressures necessary to:
– (a) provide a “wall of pressure,” preventing expanding
hot gas from exiting through the engine inlet as well as
through the exhaust;
– (b) provide the proper ratio of air-to-fuel for efficient
combustion and cooling of the combustion chamber.
• Pressure decreases through convergent ducts and
increases through divergent ducts,
Pressure ~ Temperature
Relationship
Continuous Cycle
 GAS TURBINE BASIC PRINCIPLES

• In (F), fuel is injected between the compressor and the turbine to further
accelerate the air mass, thus multiplying the force used to drive the
load.
• In (G), the motor is removed and the compressor is powered by a
portion of the combustion gas, thus making the engine self-sufficient as
long as fuel is provided.
• In (H), a typical gas turbine-engine operation is represented. Intake air
is compressed, mixed with fuel and ignited. The hot gas is expanded
across a turbine to provide mechanical power and exhausted to
atmosphere.
 GAS TURBINE BASIC PRINCIPLES

• The air, which has weight and occupies space, has by definition,
mass. The mass of the air is proportional to its density, and
density is proportional to temperature and pressure.
• Air molecules are driven farther apart as temperature increases
and closer together as temperature decreases, as stated in
Boyle's and Charles’ law (PV/T = K).
– Charles ~ the volume of a gas increased with the temperature
– Boyle ~ the product of the pressure and volume are observed to be
nearly constant
• This force increases as mass and acceleration increase, as
stated in Newton’s second law (F =MA).
• Newton’s third law. (Every action produces an equal and
opposite reaction.)
 SAFETY
• When entering the gas turbine enclosure, the following
requirements must be met:
– The gas turbine will be shut down or limited to core idle power.
– The fire extinguishing system will be made inactive.
• The enclosure door shall be kept open. If the gas turbine is
operating, an observer shall be stationed at the enclosure
door, and confined space entry procedures will be followed.
– Avoid contact with hot parts, and wear thermally insulated gloves, as
necessary.
– Ear protection will be worn if the gas turbine is operating.
– Do not remain in the plane of rotation of the starter when motoring
the gas turbine.
– When performing maintenance on electrical components, turn off
electrical power to those components, except when power is
required to take voltage measurements.
 SAFETY
• GAS TURBINE OPERATIONAL HAZARDS
– The gas turbine is a source of considerable noise. It is necessary for
personnel working on the gas turbine or in its vicinity to wear proper ear
protection equipment when it is operating.
– The gas turbine is a high-speed machine. In case of component failure,
the skid housing would contain compressor and turbine blade failures, but
might not contain major compressor or turbine disk failures.
– Operating personnel shall not be permanently stationed in or near the
plane of the rotating parts.
– Low-pressure, high-velocity airflow created by the compressor can draw
objects or personnel into the engine. Although an inlet screen is used,
personnel should not stand in front of the inlet while the engine is
operating.
 SAFETY
• COMPRESSED AIR HAZARDS
– Air pressure used in work areas for cleaning or drying operations
shall be regulated to 29 psi or less.
– Use approved safety equipment (goggles or face shield) to prevent
injury to the eyes.
• PROCEDURAL HAZARDS
– Observe all specified and logical safety practices when assembling
or disassembling the engine.
• TOOLING HAZARDS
– Improperly maintained tools and support equipment can be
dangerous to personnel, and can damage gas turbine parts.
• GAS TURBINE OPERATIONAL HAZARDS
– The outside surfaces of the engine are not insulated; therefore,
adequate precautions shall be taken to prevent operating
personnel from inadvertently coming into contact with these hot
surfaces.
 SAFETY
• HEALTH HAZARDS
– Use all cleaning solvents, fuels, oil adhesives, epoxies, and
catalysts in a well-ventilated area.
• ENVIRONMENTAL HAZARDS
– The disposal of many cleaning solvents, fuels, oils, adhesives,
epoxies, and catalysts is regulated and, if mismanaged, could
cause environmental damage.
• FIRE HAZARDS
– Keep all cleaning solvents, fuels, oil, esters, and adhesives away
from exposed-element electric heaters, sparks, or flame.
• ELECTRICAL HAZARDS
– Use extreme care when working with electricity. Electricity can
cause shock, burns, or death.
 COURSE DESCRIPTION
• This training course will provide adequate system and
subsystem operational information to achieve maximum
equipment efficiency.

• This course will cover the following:

– Gas turbine fundamentals, theory of operation, and details of
construction
– Gas turbine support systems and equipment flow and
instrument diagrams (F&ID)
– Generator fundamentals, theory of operation, details of
construction
– Control system fundamentals, theory of operation, details of
construction
 PURPOSE OF THE COURSE
• This training course will familiarize Plant Operators
with the basic operation of the gas turbine-
generator (GTG) set, alternating current generator,
and subsystems that make up the GTG set
package.
 FLAME-STABILIZING AND
GENERAL-FLOW PATTERNS
• The temperature of the flame illustrated in the
center of the combustor is approximately 3200° F
at its tip when the engine is operating at full load.
• Are Metals in combustion chamber construction
capable of withstanding temperatures in this
range?
• Air flowing into the inner chamber is directed
through small holes to shape the flame centering it
within the chamber, to prevent its contact with the
chamber walls.
• What % of airflow is used for Combustion and
Cooling/Flame Shaping?
 INLET GUIDE VANES
• Inlet guide vanes direct, or align, airflow into the
first rotating blade section where velocity is
increased by the addition of energy.
• The following stator vane section is divergent,
providing an increase in static pressure and a
decrease in air velocity.
• Each subsequent stage provides an incremental
increase in velocity and static pressure until the
desired level of pressure and velocity is reached.
 GE LM6000

AUXILIARY SYSTEMS
INSTRUMENTATION
 GE LM6000

SUPPORT SYSTEMS
 TURBINE LUBE OIL SYSTEM
• The LM6000 gas turbine uses synthetic (MIL-23699, Mobil
Jet Oil II, Exxon Turbo Oil 2380, Castrol 5000) lube oil to:
– Lubricate and cool turbine bearing and gearboxes
– Provide oil to the Variable Geometry control system
• VIGV System
• VBV System
• VSV System
– Lubricate the over-running clutch for the hydraulic starter motor
• Synthetic lube oil is used because it can operate at higher
temperatures than the mineral oil in the generator lube oil
system.
 TURBINE LUBE OIL SYSTEM
• The LM6000 lube oil system has two distinct subsystems:
– Pressurized supply system
– Separate scavenge system, which suctions or “scavenges” oil from
the bearing lube oil sumps.
• Each subsystem has its own filters.
– A multi-element lube oil pump, containing both supply (one (1)
element) and scavenges elements (six (6) elements), circulates oil
through the system.
• A reservoir, lube oil coolers, piping, valves, and
instrumentation complete the system.
• These lube oil components and their operations are
described below.
 TURBINE LUBE OIL SYSTEM
• Turbine Lube Oil Supply Filters
– 6 micron
– Handle 100% flow each
– Collapsed rated at 150 psid
• Turbine Scavenge Oil Filters
– 6 micron
– Handle 100% flow each
– Collapsed rated at 150 psid
• Air/Oil Separator
– 6 micron
– Collapsed rated at 150 psid
150 gal
500 gallons
 GENERATOR LUBE OIL
SYSTEM
• The Generator Lube Oil System has two distinct
subsystems:
– the pressurized supply system
– The jacking oil system.
• Lubricating oil is provided during startup, operation, and
coast down to prevent damage to the generator bearings.
• The jacking oil pump is used during startup to provide high-
pressure oil to lift the shaft up on a layer of oil to ease the
break-away friction between the generator bearing
surfaces and to axially center the shaft with the generator
thrust bearing.
 GENERATOR LUBE OIL
SYSTEM
• The Generator Lube Oil System uses an alternating current
(AC)-driven pump, a generator shaft-driven pump, and four
partial rundown tanks.
• When speeds rise above approximately 400 RPM, the
bearings are lubricated by oil from the shaft-driven pump,
which is mounted outboard from the assembly.
• Lubricating oil is provided by the AC-driven pump during
startups and shutdowns.
• The AC-driven pump also serves as a backup in case the
shaftdriven pump fails.
 GENERATOR LUBE OIL
SYSTEM
• The AC-driven pump is supplemented by four partial
rundown tanks during shutdowns and failures.
• Oil from the rundown tanks flows by gravity to lubricate the
bearings as the rotor speed drops (20 gallons each).
• The generator bearings are pressure-lubricated, babbitt-
sleeve types.
• The bearing faces are grooved for even oil distribution and
the drive-end bearings incorporate thrust pads to limit fore-
and aft-movement of the generator rotor.
• Labyrinth seals and oil slingers are mounted on the
generator rotor shaft to prevent oil leakage from the
bearing housings.
HP –2850 psig - Pushes
LP – 800 psig – Lifts/Pushes
5 micron

10 micron

10 micron
 HYDRAULIC START SYSTEM
• The LM6000 Hydraulic Start System supplies hydraulic
pressure to the hydraulic starter motor to rotate the HP
compressor low-speed and high-speed cranks for gas
turbine (GT) during light off to bring the GT to idle speed.
• The Hydraulic Start System also maintains unit rotation
during all GT shutdowns with the exception of a “Fast-Stop
Lockout without Motor” (FSLO).
• The normal start sequence energizes the drive motor at the
10-second interval if all permissives are satisfied.
• The drive motor is de-energized when XN25 speed is
greater than 4,600 RPM.
• During FSWM, the starter is engaged for 25 minutes when
XN25 speed reaches 1,700 RPM. During CDLO, the starter
is engaged for 20 minutes when XN25 speed reaches
1,700 RPM.
 HYDRAULIC START SYSTEM
• The drive motor provides the motive force for the three
pumps that make up the hydraulic pump assembly:
– Charge pump,
– Main hydraulic pump,
– Oil cooler pump.
• The charge pump takes a suction from the reservoir and
discharges to the suction of the main hydraulic pump to
provide a net-positive suction head to the main hydraulic
pump.
• The main hydraulic pump supplies high-pressure oil to the
GT hydraulic starter motor located on the GT accessory
gearbox.
• The GT starter motor provides the motive force to spin the
GT high-pressure compressor (HPC)
 HYDRAULIC START SYSTEM
• Most of the oil flows from the GT starter motor back to the
main hydraulic pump suction, with some oil flowing through
the GT starter motor casing drains to the temperature
control valve (TCV).
• The TCV controls oil temperature by routing the oil directly
back to the reservoir or diverting a portion of the oil to the
air-cooled oil cooler.
• The oil cooler is air cooled by a hydraulic motor-driven
cooler fan.
• The oil cooler pump provides the hydraulic pressure to
drive the cooler fan, taking suction on the reservoir and
discharging through the cooler fan motor.
• The discharge from the cooler fan motor is returned to the
reservoir.
SOV-1619: Control the angle
of the main hydraulic pump
variable displacement swash
plates to control pump output
and thus control the speed of
the GT starter motor.
 FUEL GAS SUPPLY SYSTEM
• The Fuel Gas Supply System provides gas fuel in sufficient
amounts to run the GT through the full range of rated
output.
• The system provides compression, filtering, and cooling of
the natural gas supply to ensure it meets the LM6000 fuel
specifications.
• The Fuel Gas Supply System is required to furnish fuel gas
to meet GE specifications of:
– 430 MMBtu/hr maximum
– 250°F maximum
– 675 ± 20 psig
– Filtered to 3 microns
 FUEL GAS SUPPLY SYSTEM
• The Fuel Gas Supply System interfaces with the following
systems:
– Compressor Discharge Pressure (CDP) Purge System
– Water Injection System – provides demineralized water to maintain
combustion chamber temperature at the proper value to control
NOX and CO emissions.
• Fuel shutoff valves manage gas flow to the combustor.
• Solenoid piloted fuel shutoff valves FSV-6249 and FSV-
6204 are quick-closure valve assemblies located upstream
and downstream, respectively, from the gas fuel vent
valve.
• These fail-close valves are either fully open to allow fuel
flow or fully closed to prevent fuel flow.
 FUEL GAS SUPPLY SYSTEM
• During startups, the control system first opens
shutoff valves FSV-6249 and FSV-6204.
• At shutdown, fuel gas is vented from the shutoff
valves and interconnecting supply line by two
paths.
– Quick exhaust valves in each assembly allow rapid
closure of valves and vent gas to a safe area.
– The shutoff valves actuators are vented to a safe area.
• Solenoid-operated valve SOV-6208 opens to vent
the fuel supply line between the shutoff valves.
 VENTILATION & COMBUSTION AIR
SYSTEM
• Turbine Enclosure Ventilation Air System – Provides the
gas turbine enclosure with sufficient air to cool the exterior
of the turbine and inside the enclosure.~ Vacuum
– Outside air flows through screens and filters in the filter house. The
filter house has dual, identical left- and right-hand and upper and
lower sections.
– The fans are belt driven by electric motors. Normal operation is to
run one fan with the other as a backup.
– The turbine enclosure maintains a negative pressure, with respect
to the generator enclosure, to prevent any gas migration from the
GT to the generator enclosure.
– Each turbine enclosure ventilation exhaust fan has a fire damper on
the inlet side of the fan. On a GT “Fire Stop,” the fire dampers are
closed by CO2 pressure to stop all airflow from the enclosure.
 VENTILATION & COMBUSTION AIR
SYSTEM
• Generator Enclosure Ventilation Air System – Provides the
generator enclosure with sufficient air to cool the generator
and the inside of the generator enclosure.~ Positive
Pressure
– Generator ventilation air is provided from the same filter house as
the turbine enclosure. Generator enclosure air, however, is
supplied to the enclosure by one of two redundant supply fans.
– A backdraft damper is mounted on the discharge of each generator
enclosure fan to prevent airflow through the nonoperating fan.
– A fire damper is mounted on the inlet of the generator ventilation
exhaust duct. The fire damper is closed on a GT “Fire Stop” signal
by CO2 pressure to stop all airflow out of the enclosure.
• Turbine Combustion Air System – Provides the LM6000
with sufficient combustion air to operate at all required
levels.
– Combustion air enters the filter house and flows through the guard
filter and chiller coils The chiller coils cool the combustion air to
 COMPRESSOR WATER WASH
SYSTEM

• There are two washing modes provided:

– (1) on-line mode when the engine is running and under load,
– (2) off-line mode when the engine is not running, and the
compressor is being rotated by the Hydraulic Start System.
• Off-line washing is more effective than on-line washing.
• The features of the Compressor Water Wash System
include the following:
– Vent with 40-micron filter in the reservoir fill cap
– Filters at each ring manifold inlet
– Pressure indicator on the ring manifold line, which should read 80
to 120 psig during system operation
– Analog flow-rate indicator in the manifold feed line, which should
read 5 to 8 gpm
– A manual regulator valve upstream of the flow-rate indicator to
adjust flow-rate
 COMPRESSOR WATER WASH
SYSTEM

• Separate nozzle rings are provided in the engine air inlet

for on-line and offline cleaning.
• Droplet size is larger in the off-line ring, which allows
greater flow volume than when the engine is running under
load.
• The on-line droplets are smaller to avoid blocking
compressor blades at speeds above core idle.
• Flow is controlled by a separate on-line and off-line control
solenoid operated valve (SOV) located on the engine
water-wash nozzle manifolds.
• The wash sequence is initiated by a local pushbutton
mounted on the water wash skid.
• The operator selects on-line or off-line modes on the
“CTRL PANEL HMI” screen.
 SPRINT SYSTEM (E-SPRINT)

• The SPRINT System (spray intercooling) cools the LM6000

combustion air to enhance the performance of the gas
turbine (GT).
• The output of the GT is limited by the combustor inlet
temperature.
• The SPRINT System begins a mist injection process at
approximately 35 MW while the turbine approaches full-
load operation of 48 MW.
• The mist injection lowers the combustor inlet temperature
and permits greater power output on hot days when the
LM6000 cannot reach its maximum rated mechanical
power output.
• SPRINT provides no benefits when the GT operation is at
less than full load.
 SPRINT SYSTEM (E-SPRINT)
• SPRINT intercooling reduces:
– (LPC) inlet temperature (T2)
– (HPC) inlet temperature (T25),
– which in turn lower the LPC discharge temperature
(T25) and the HPC discharge temperature (T3).
• All lower the combustor inlet temperature,
permitting more power output.
 SPRINT SYSTEM (E-SPRINT)
• System operating pressures, temperatures,and
flowrates are provided with the following
indicators:
– SPRINT permissive “PS3 MIN. OK”
– SPRINT permissive “T2 TEMP. > 30°F”
– SPRINT permissive “8TH STAGE PRESS OK”
– “SPRINT SHUTDOWN” indication
• Controls are also provided to enable and disable
the system and to take manual or automatic
control.
• Manual control allows the operator to adjust the
flow-demand setpoint
115 kv
 FIRE PROTECTION SYSTEM
• The Fire System is designed to protect the gas turbine
(GT) generator and facility equipment.
• The Fire System includes the following equipment:
– Firewater loop
– GT Generator CO2 Fire Suppression System
– Gas Compressor CO2 Fire Suppression System (2)
– Local portable fire extinguishers
• Caution:
– Before entering the turbine/generator or GT enclosures, ensure that
the CO2 system is deactivated.
– The CO2 isolation valve must be manually closed to deactivate the
system.
– When exiting the enclosure, ensure that all doors are closed and
the system is placed back in service.
• Alarm horns will sound if fire or gas is detected. CO2 is
released 30 seconds after the alarm horns sound. A
manual key-switch is provided as a “Horn Acknowledge”
t it h
 FIRE PROTECTION SYSTEM
• Note:
– If the alarm conditions causing the strobe lights to
activate include CO2 discharge into the enclosure, the
CO2 Discharge Pressure Switch engages the latch-in
relay in the Enclosure
– Purge Switch to “lock” the strobes ON.
– The continually flashing strobes provide an additional
reminder that the enclosure MUST be purged of CO2 to
restore a safe condition for personnel to enter.
– The strobes will remain ON until all alarm conditions are
cleared through the Fire Control Panel, the key-
operated Enclosure Purge Switch is used to disengage
the strobe latch-in relay.
 VIBRATION MONITORING SYSTEM

• The vibration monitoring system produces vibration

magnitude data with adjustable alarm and shutdown set
points for engine and generator safety.
• Aft and forward engine accelerometers are installed on the
turbine rear frame (TRF) and compressor rear frame
(CRF).
• These sensors produce complex electrical waveforms,
resulting from the frequency and amplitude of engine
vibration.
– Engine (FWD) vibration velocity at (HPC) speed
– Engine (AFT) vibration velocity at (HPC) speed
– Engine (FWD) vibration velocity at power turbine (LPT/LPC) speed
– Engine (AFT) vibration velocity at power turbine (LPT/LPC) speed
 GE LM6000

ELECTRICAL SYSTEM
 AC
DC

AC

MAVR DC
Brushless Excitation
 ELECTRICAL SYSTEM
• The exciter assembly consists of a permanent magnet alternator
(PMA), an exciter stator and rotor, and a rotating diode rectifier.
• The PMA stator consists of a single-phase winding in a
laminated core.
• Twelve permanent magnets rotate on the rotor inside the stator
to produce approximately 125 VAC at 60 Hz.
• The PMA output AC voltage is rectified and regulated by the
Modular Automatic Voltage Regulator (MAVR).
• The exciter stator, which receives the MAVR output DC voltage,
is mounted around the exciter rotor. It consists of a stationary
ring that supports the stator poles and carries the magnetic flux
between adjacent poles. Stator windings are series-wound
around laminated poles.
• The exciter rotor is constructed from punched laminations and
contains resin- impregnated, form-wound, and three-phase
windings. A rotating diode assembly rectifies the AC voltage
induced into the exciter rotor.
 ELECTRICAL SYSTEM
• The electrical generator produces electricity at 13.8 kV and
supplies power to the Electrical System when the GT is
operating at load.
• The generator is connected to the generator circuit breaker
through a cable bus.
• The generator circuit breaker is contained within the 13.8-
kV switchgear.
• The breaker is capable of isolating the generator from the
Electrical System.
• The cable bus transmits electric power from the generator
to the 13.8-KV switchgear.
• The cable bus also connects the 13.8-kV switchgear to the
generator step-up transformer.
 ELECTRICAL SYSTEM
• There are 3 separate DC systems:
– 125-Vdc system
– Two 24-Vdc systems.
• The 125-VDC system provides power to the generator
step-up transformer protective relay panel and switchgear
breakers that require a reliable power supply with battery
backup for their controls.
• The GT control 24-VDC system provides power for the
turbine and generator monitoring and control circuits.
• The fire protection 24-VDC system provides power for the
fire protection and detection devices and the fire alarm
panels.
The The fuses
redundant provide
diode over-current
configuration protection an
enables the allow
exciter to continued
normal
carry full operation,
generator unless two
output with fuses open in
as many as any one of th
half the six rectifier
diodes out of legs.
service
• The rectifier is a three-phase, full-wave bridge
rectifier with parallel, individually fused diodes.
• The fuses are mounted on the reverse side of the
diode assembly.
• The redundant diode configuration enables the
exciter to carry full generator output with as many
as half the diodes out of service.
• Because diodes have only two failure modes
(shorted or open), the fuses provide over-current
protection and allow continued normal operation,
unless two fuses open in any one of the six
rectifier legs.
GE LM6000

SEQUENCES
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LETS REVIEW NORMAL START
SEQUENCES IN TRAINING
MANUAL
LETS REVIEW NORMAL STOP
SEQUENCES IN TRAINING
MANUAL
 LETS REVIEW
TYPICAL FAULTS ALARMS &
SHUTDOWNS IN TRAINIG
MANUAL