hydro generator brochure

8/12/2019 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

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