Hydro Generator Brochure
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Transcript of Hydro Generator Brochure
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SynchronousHydro GeneratorsHorizontal & Vertical Applications
Power: 2,000 37,500 kVA
Speed: 150 900 RPMVoltage: 3,000 13,800 Volts
Frequency: 50 & 60 Hz
GE Energy
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Weve manufactured generators forover 100 years.GE has the capability to design and manufacture electricalmachines for the most stringent application requirements. Thiscentury of achievement has built a rich tradition of technicalexcellence, quality and reliability.
IndustryPower Generation Hydro Energy
ApplicationThis line of synchronous generators has been specically designedin response to the growing demand of small hydro plants. Itincorporates a full range of features to address the applicationsand operational conditions demanded by this industry. Thisproduct line is customized for horizontal & vertical hydro turbine
applications in a range of 2,000 37,500 kVA, 150 - 900 RPM.
GE Advantages
Rugged & compact design. Easy installation. Reliable operation. Shipped assembled or disassembled, based on customer request
Compact construction with a small foundation
The rigid mechanical conguration (shorter distance betweenbearings) allows for low vibration levels
Follows critical industry trends for simple, modular andintegrated designs
Proven GE insulation system makes for a durable andreliable machine
Modularized construction for fast and easy site installation
Rotor designed to meet higher runaway speeds specic to hydroapplications for Francis and Kaplan turbines
Experience Matters
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Construction
FrameThe stator frame is made of weldedsteel construction and manufacturedwith thick steel plates to prevent
distortion during operation. Robustand rugged, these frames aredesigned to withstand the mass ofa stator core, bending stresses anddeections. The frames are designedto minimize vibrations and noiselevels. The frame bore is machined toensure a uniform air gap between therotor and stator, thereby minimizingthe unbalanced magnetic pull. Theseframes are designed to withstand theextreme stresses due to short circuits.
Each machine is designed to beassembled on a robust concretefoundation or steel base. A minimumof four lifting points is provided in thegenerator to facilitate this process.Larger or heavier machines, whichare shipped disassembled, arereassembled over the foundationat the site, as a part of the eldinstallation process.
The frame is fabricated from structuralsteel plates to ensure an extremelyrobust and rigid support structure. Thegenerator can be designed for openenclosure and totally enclosed water-to-air cooled. The exciter and rectierhub are mounted at the non-driveend (NDE) enabling easy access formaintenance purposes.
Stator CoreThe stator core assembly consists of
segmented and insulated laminations
of cold-rolled low-loss silicon steel,
clamped between substantial side
plates. Laminations are stacked upwith a controlled burr in order to
ensure minimal losses. Lamination
steel is selected based on project
requirements. The core is built inside a
structural cage, which is then inserted
into the frame and attached through
weldments. Steel I-beam spacers
spot welded to low carbon steel
laminations form radial ventilation
ducts along the core length. When
core building is complete, the wholeassembly is clamped under pressure
with studs. The nuts and compression
plates are welded in place while
maintaining pressure.
Laminated PolesThe rotor has laminated poles tted
with strip or wire wound
eld coils and supplied with an
amortisseur winding on the
outer pole face.
Laminated SpiderThe rotor spider is made of thin
laminations, clamped with axial
studs. According to design needs,there are axial holes to improve the
air ventilation through the rotor. The
laminated poles are attached to the
spider with dovetails.
Solid SpiderThe rotor spider and shaft are
obtained from a one-piece machined
carbon steel forging. According to
design needs, there are axial holes to
improve the air ventilation throughthe rotor. The laminated poles are
xed on the spider by using dovetails
on the pole bottom.
Rim SpiderThe rim is made of forged steel.
The rim is shrunk on to a large web
that is attached to the shaft by
means of a hub and a key, then pole
bodies are attached to the rim via a
number of radial bolts.
Twoaxial or radial fans (according
to design characteristics) are
mounted on the shaft to provide
airow to maintain the machine
temperature within the limits
specied. The fans are used to
provide double-ended ventilation,
helping ensure an even temperature
distribution across the eld and
stator windings.
RotorThree types of rotor construction
can be utilized in this product line:
a laminated spider with dovetailed
poles, a rim spider with bolted poles, or
a solid spider with dovetailed poles.
Rotor with shaft-mounted out board exciter
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Even stator coil spacing maintains the electrical and mechanical integrity of the machine.
Insulation
Mica composite, epoxy resin andvacuum-pressure impregnation(VPI) provide a robust and reliableinsulation system.
The advanced insulation systemon all large machines will typicallyreward you with years of reliableoperation. GEs insulation system isdesigned to minimize the eect oflocalized electrical stress and reducethe eects of partial dischargewhile increasing machine life andreliability. Components are selectedto ensure reliability of the system asa whole.
The insulation system can meetapplicable standards. All woundstators undergo global vacuum-pressure impregnation (VPI)treatment. Curing binds the statorcomponents into a solid and rigidstructure with excellent dielectricstrength, dimensional stability andmechanical strength. It also increasesthe resistance of the winding tothermal shock, moisture and other
contaminants.
The binding agent used is GEs thirdgeneration epoxy resin, selected andtested to IEEE-1776 for chemicalcompatibility, thermal/dimensionalstability, and electrical properties.
The coil turns in the slot section arebonded using heat and pressure toachieve dimensional accuracy of thenished coil.
The mica composite insulation is designed for
uniform ground insulation dielectric strength.
Above 6000 volts, a semi-conductingpaint is applied to the slot portion andgraded beyond the core to providecorona protection.
A protective armor of heavyglass tape is used for protectionagainst mechanical shock andabrasion.
CopperConductor
Ground WallInsulation
TurnInsulation
StrandInsulation
Coil InsulationOnce assembled, the coils are insertedinto the stator slots and the endconnections are brazed and taped.GEs coil lock bracing system supportsthe coils and makes the entirestructure more rigid.
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Brushless exciter complete with rectier hub
Excitation
Brushless Excitation
SystemThe exciter is a three-phase AC
generator with a rotating three-phase bridge rectier.
The exciter stator core is madeof laminated, hot rolled or coldrolled steel, held together by steelendplates.
The DC eld coils are wound in aconcentric pattern using formersand mounted on the frame poles.
The whole assembly undergoes avarnish treatment.The exciter rotorarmature consists of a three-phasewinding system. The core consistsof steel laminations that are stackedand held with end plates and wound
with enamel covered round copperwire. The whole assembly thenundergoes a varnish treatment.
The rectier hub includes liberallyrated diodes. The leads from thearmature are connected directlyto the hub, and the two DC outputleads from the hub are connectedto the main eld and clamped toprevent movement.
The exciter armature and rectier hubare assembled by interference ontothe shaft. The complete exciter andrectier hub assembly is enclosed
in a steel sheet cover. For ease ofmaintenance, a removable plategives access to the rectier hub.
As a protection for the diode bridgeunder normal conditions, a varistoris supplied in parallel with therectier hub.
Collector Ring with
BrushesThe brushes are electrographitetype, open terminal. The quantity ofbrushes is determined taking into
account the current density requiredfor an ecient working of theexcitation system. The brush holdersare selected in order to provide therequired contact pressure betweenthe brushes and the collector rings.
The collector rings are low carbonsteel material, providing thermalconductivity required to keep thesystem at the temperature levelaccording to applicable standards.There are two kinds of collectorrings: smooth (standard) andgrooved rings (for special cases).
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Bearings
Bearings
Vertical
There is a standard arrangement forthe bearings conguration: thrust andguide bearing at NDE side and onlyguide bearing at DE side.
NDE thrust bearing is assembled intoa housing, which is bolted at the upperendshield, and the upper endshield isbolted against the stator frame.
NDE guide bearing works in contactwith a thrust block, which is the piecethat connects the rotor shaft to thethrust bearing surface, by means of akey connection in the shaft.
High-pressure oil lift systems arefrequently supplied at NDE thrustbearing to allow easy start-up (due tothe high pressure at the thrust bearingsurface) and also better installationand maintenance handlings.
NDE thrust bearing is insulatedfrom the thrust bearing housing. Aremovable link is provided to groundthe drive end guide bearing and to
facilitate testing of the thrust bearinginsulation.
DE guide bearing is assembled atthe lower endshield, together with itssupport, and it works in contact with atrack built in the rotor shaft.
Lower endshield is bolted against thestator frame, and it is positioned at theinner side of the stator frame.
All the components assembled at thelower endshield (DE guide bearing,supports and covers) are split, in orderto permit the assembling process (dueto rotor shaft ange diameter, usuallylarger than DE guide bearing innerdiameter). The access to those piecesis done by means of openings in thelower endshield, which is closed afterthe assembly process is nished.
Horizontal
There are normally two sleevebearings, each mounted on a pedestal
that is bolted to the base. Eachbearing liner is made from steel, linedwith white metal and is split on thehorizontal centerline. The standardtwo-bearing arrangement (whichcan be varied, by agreement, to suitthe type of coupling used) assumesa limited end-oat coupling, andnon-locating bearings are provided.(Typical end-oat is inches).
Thrust bearing can be provided onthe DE or NDE side, according torequirements.
Oil throwers on the shaft andoil seals on the pedestal areprovided to prevent oil leakage andcontamination. High-pressure oillift systems are frequently suppliedat each bearing to allow for easyinstallation and maintenance.
NDE bearing liner is insulated fromthe bearing housing. A removable linkis provided to ground the drive endbearing and to facilitate testing of thebearing insulation.
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Cooling System
Enclosure and
VentilationThe generator is designed for open
enclosure (WPI, IP23/24) or totallyenclosed air-to-water (TEWAC/CACW)cooling system (top or bottom cooling).
Air is circulated inside the machine
by two internal fans and the rotor.The radial ducts in the stator core,the design of the end windings and acareful review of the air path, ensuretemperature uniformity in all parts ofthe machine.
Top Mounted Cooling
Bottom Mounted Cooling
Cooling circuit for vertical generators
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Options and Accessories
Permanent Magnet Generator
(PMG)PMG supplies continuous power to the exciterthrough the voltage regulator in order tomaintain up to 300% short circuit current from
the alternator during a fault condition. It providesfull exciter power, regardless of the generatorvoltage.
Neutral Grounding Resistor (NGR)The NGR acts to limit generator fault current to a low level when a phase-to-ground fault occurs. It also serves to protect the generator from excessively highmagnetic stresses and temperatures caused by high fault currents. The NGR istime-rated.
AVR
EXCITER
ARMATURE
BRUSHLESSEXCITER
SYNCHRONOUSGENERATOR
ROTOR
FIELD
STATOR
WINDINGS
CT
PT
GCB
SYSTEM
BUS
NGR
1000A
EXCITER
FIELD
SETPOINT
INPUT
AUTOMATIC VOLTAGE REGULATOR
(DECS UNIT OR EQUIVALENT)
CT
PT
FIELD
OUTPUT
PMG
POWER IN
IDC
(3A
to
15A)
DIODE
RECTIFIER
10 or 30
0 8
EXE
PERMANENTMAGNET
GENERATOREXCITER
FIELD
(PERM. MAGNET)
PMG
ARMATURE
10
or
30
I
I I I
I
I
I
I
I
I I
II
I
I
I I
I
I
CT1 (1)
NEUTRAL
CURRENT
13,800:120/240 V
10A/10 sec
50/5A, C10HEATER
RS
Automatic Voltage
Regulation (AVR)The AVR utilizes a fast response
microprocessor to control its AC to DCconverter power stage output thatprovides excitation to the generatorto regulate the dierence betweenthe generator stator voltage referenceset point and feedback signal tozero. Reactive power sharing duringparallel operation of generator withother generators or a power systemis achieved by the use of droopcompensation where the voltagefeedback signal is increased bytypically 0% to 5% as lagging reactiveload current increases from 0% to100%. The following four operatingcontrol modes with a bumplesstransfer between modes are availableto suit the site requirements:
Sequence of events recording& oscillography, which is usefulduring commissioning diagnostics
AVR automatic voltage regulation(with switchable reactive powerdroop compensation for basicparallel operation)
Generator PF power factor control(for connection to large powersystem)
Generator VAR reactive powercontrol (for connection to largepower system)
Brushless exciter eld current(manual mode) regulation
Other functions of the AVR include:
Voltage soft-start build up
Minimum and maximum excitation
and stator current limiters
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Accessories Partial discharge sensor kits
Bearing RTD (Resistance
Temperature Detector)
Space heater 50/60 Hz
Large oversized fabricatedsteel main terminal box framemounted
Fabricated steel neutral terminalbox frame mounted
Surge Arrestors and/or SurgeCapacitors
Current and Potential Transformers
Vibration monitoring equipment Water leakage detector
Couplings
Generator control and protectionpanel optional
Medium voltage switchgear optional
Remote Monitoring and
DiagnosticsGEs comprehensive industrialmachine monitoring strategy isdesigned to enhance the capabilitiesof industrial customers to reducedowntime and identify industrialmachine failure before it happens.Elements of GEs solution include: Continuous technical support
through the GE Monitoring andDiagnostic (M&D) Center
GE engineers with remote
access to motor condition datacan identify potential failures ofindustrial machines
Advanced technology productsdesigned to easily retrot existingcustomer equipment and providethe highest levels of protectionand reliability
Installation and commissioning prompt comprehensive servicebuilt upon GEs years of eldengineering experience, OEM
product knowledge, and access toproduct information
Terminal box with lightning arresters, surge capacitors and current transformers
Features
GE can provide a complete motormonitoring solution: Comprehensive motor condition
monitoring
Text message/email alerts
24-hour monitoring support
24-hour engineering support
Warehoused condition data
Web-based access for customervisualization of data
Wireless transmission of data
GE oers several options for theremote monitoring of your industrialasset. The parameters identiedherein are congurable based oncustomer/application need. GE iscommitted to complete customersatisfaction and will work to ensurethe monitoring package chosen
will serve the customers individualneeds.
Benefts
Wireless network reducesinstallation (cabling) costs
Predictive maintenance intervalsstreamline maintenance schedulesbased on actual operatingconditions
Reduced maintenance costs
Increased machine productivity
Increased operating eciency
Minimize risk of catastrophicdamage to equipment
Quick installation with minimaldisruption to operations
Minimal footprint - installs on anyaccessible DIN rail
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Testing
The Right Choice
Test CapabilityGE has world-class test facilities.
Extensive experience in the
performance of rotating machinery
with all forms of xed and variable
speed drives has been accumulated.
Each machine is tested at the
factory before shipment for
installation in the eld, thus reducing
set-up time.
Power Solutions Team
Experienced application engineers are available to solveyour toughest generator system challenges.
Installation, Start-up & Commissioning
Experienced engineers/technicians available to
support site erection, installation and commissioning
Long term service agreements including remote
monitoring and maintenance assistance
Parts center supports your local needs and helps
assure your up-time requirements.
In-Process Testing
Rotor impedance, surge test;
AC dielectric tests, prior to VPI
Running Tests According toInternational Standards:
NEMA MG1/IEEE 115, IEC 60034-1
& 60034-2 or ABNT 5052
For more information, please contact your GE sales representative.
GE Energy
800 541 7191
www.gemotors.com
2011 General Electric Company. All rights reserved.
GE and GE Monogram are trademarksof General Electric Company.
GEA18285
Short Circuit Test
Up to 130% of rated stator current
No Load Saturation Test
Up to 125% of rated stator volts Short Circuit Ration (SCR)
From test data
Mechanical Run
Including vibration analyses using
velometers; dynamic balancing
EciencySegregated loss method per IEEE
115
Insulation Resistance &
Polarization Index
Dielectric Tests
In the stator, rotor and brushless
exciter
Lubrication System
Functional tests