GEMotors

SeriesE-404-Pole Synchronous Generators

10 to 40 MW6.6 - 13.8 kV 50/60 Hz

1

Experience Matters In Renewable Energy

We’ve manufactured generators for over 100 years.GE Motors has the capability to design and manufactureelectrical rotating machines for the most stringent applicationrequirements. This century of achievement has built a richtradition of technical excellence, quality and reliability.

IndustryPower Generation - Renewable Energy

ApplicationsThe Series E-40 has been specifically designed in response to thegrowing demand for renewable power generation. It incorporatesall the features to address the application and operationalconditions demanded by this industry. Series E-40 generatorsare customized for steam turbine applications in a rangeof 10-40 MW.

GE AdvantagesRugged & Compact Design. Easy Installation. Reliable Operation.

• Shipped assembled allows for safe and fast installation.

• Compact construction, small foundation and better cost.

• Self aligned spherical seat bearings are supported by a robust frame construction.

• Top or bottom totally enclosed water to air cooler (TEWAC) configurations.

• The rigid mechanical configuration (shorter distance between bearings) allows for low vibration levels.

• Follows critical industry trends for simple, modular and integrated designs.

• Durability and reliability of the traditional GE insulation system is legendary.

2

Construction

Frame

The stator frame is made of weldedsteel construction and manufacturedwith thick steel plates to preventdistortion during operation. Robustand rugged, these frames aredesigned to withstand the weight ofremovable stator core, bendingstresses and deflections. The framesare designed to minimize vibrationsand noise levels. The frame bore andbearing assembly surfaces aremachined to ensure a uniform air gapbetween the rotor and stator, therebyminimizing the unbalanced magneticpull. These frames are designed towithstand the extreme stresses dueto short circuits.

Cylindrical rotor assembly on balancemachine before insertion into the stator.

Removable core rigid stator assemblyready to be mounted in the stator frame.

3-dimensional computer generated designsare used to help produce consistent high-quality components.

Removable Core StatorThe removable core stator assemblyconsists of segmented and insulatedlaminations of cold-rolled low-losssilicon steel, clamped between sub-stantially built side plates. Followingthe punching operation the lamina-tions are de-burred (if necessary)and stacked to ensure minimal losses.Laminations of 19 mils thick with C4or C5 insulation are standard. Thecore is built inside a structural cage,which is then inserted into the frameand tightened with bolts. Steel I-beam spacers spot welded to lowcarbon steel laminations form radialventilation ducts along the corelength. When core building is com-plete, the whole assembly is clampedunder pressure with studs. After afinal dimensional check, the nuts andcompression plates are welded inplace while maintaining pressure.No weld is applied to the laminatedcore to ensure minimal core losses.

Rotor

The rotor core is made of piled lami-nations. This kind of rotor configura-tion allows an increased in airflowthrough the field winding. The shaft ismade of forged steel. The machined

shaft is inserted inside the rotor coreand fixed by interference. For ratingsup to 20 MW, air enters the rotorcore by means of holes punched onthe rotor lamination. For ratingsabove 20 MW, there are no holes inthe lamination but the shaft ismachined in such a way that thereis airflow in the core. The shaftconstruction for this case is called“fluted” or “scooped”. Two axial fansare mounted on the shaft providingsufficient airflow to maintain themachine temperature within thelimits specified according to thegenerator class (B or F Rise).

Insulation

3

Coil Insulation

The homogeneous nature of the mica compositeinsulation ensures a uniform ground insulationdielectric strength superior to mica flake tapesand wrappers.

Heavy glass tape is a protectivearmor against mechanicalshock and abrasion.

Once assembled, the coils are inserted into the statorslots and the end connections are brazed and taped.GE’s Coil Lock bracing system supports the coils andmakes the entire structure more rigid.

Special care is taken at the coillead termination during tapingto assure the filling of all voidsat this critical point.

The slot sections of coils aremolded under heat and pressureto bond the strands and turnstogether assuring dimensionalaccuracy of the finished coil.

The binding agent used is GE’s thirdgeneration epoxy resin, selectedand tested to IEEE-429 for chemicalcompatibility, thermal / dimensionalstability, and electrical properties.

A semi-conducting paint is applied tothe slot portion and graded beyondthe core to provide corona protection.

Mica composite, epoxy resin andvacuum-pressure impregnation (VPI)provide a perfect insulation system.

The advanced insulation system onall large machines will reward youwith many years of reliable opera-tion. GE’s insulation systems aredesigned to minimize the effect oflocalized electrical stress and reducethe effects of partial discharge whileincreasing machine life and reliability.Components are carefully chosenfor compatibility with the systemas a whole. The insulation systemis subjected to rigorous testingaccording to applicable IEEE, IEC andNEMA standards. All wound statorsundergo global vacuum-pressureimpregnation (VPI) treatment.This process utilizes automatedcapacitance monitoring to ensurethat each stator winding is fully

impregnated with epoxy resin.After curing, it 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 othercontaminants. Copper

Conductor

Ground Wall Insulation

Turn Insulation

Strand Insulation

Even stator coil spacingmaintains the electrical andmechanical integrity of themachine.

Excitation

Brushless ExcitationSystemThe exciter is a three-phase AC gen-erator with a rotating three-phasebridge rectifier to give DC output.

The exciter stator core is made oflaminated, cold rolled and coldannealed steel, held together bysteel endplates.

The DC field coils are wound in aconcentric pattern using formersand inserted in the slots of thepolar pieces.

After which, the whole assemblyundergoes a complete VPI (VacuumPressure Impregnation) treatment.

The exciter rotor armature consistsof a three-phase winding system.The core consists of low-loss var-nished laminations that are stackedand held with end plates and woundwith enamel covered round copperwire. The whole assembly thenundergoes a complete VPI.

The rectifier hub includes liberallyrated diodes. The leads from thearmature are connected directly tothe hub, and the two DC output leadsfrom the hub are connected to themain field and clamped to preventmovement. The exciter armature andrectifier hub are bolted directly to aflange machined as an integral partof the shaft. The complete exciterand rectifier hub assembly isenclosed in a steel sheet cover, with aremovable plate to give access to therectifier hub on stopped conditions.

As a protection for the diode bridgeunder normal conditions,a discharge resistoris supplied inparallel with therectifier hub.

Complete brushless exciter mountedon the rotor shaft.

4

5

Bearings

The generators are designed with a water-to-aircooling system in either a top or bottom configu-ration. Air is circulated inside the machine by twointernal fans and the rotor. The radial ducts in thestator core, the design of the end windings and acareful review of the air path, ensure tempera-ture uniformity in all parts of the machine.

There are two sleeve bearings, eachmounted by a rabbit fit on a stiff end-plate. In-board air seals are providedto supplement the oil seals to preventany oil leakage into the machineenclosure.

The void between the oil seal and airseal is maintained at atmosphericpressure to eliminate the possibilityof low pressure, caused by coolingair, drawing in oil. Each bearing lineris made from steel, lined with whitemetal and is split on the horizontalcenterline.

The standard two-bearing arrange-ment allows 0.5 inch axial displace-ment. A low-pressure oil supply isrequired and is normally taken froma separate oil system.

Each bearing has a sump and usuallyan oil ring for lubrication during run-down. Oil throwers on the shaft andoil seals on the bearing housing areprovided to prevent oil leakage andcontamination.

Stub pipes are usually supplied (oneinlet and one outlet per bearing) fit-ted with an orifice plate on the oilinlet to control the oil flow rate.By arrangement these pipes can beconnected to provide a single inletand a single outlet to the machinefrom carbon or stainless steels.

Both bearing liners are insulated fromthe bearing housing. A removable linkis provided to ground the drive endbearing and to facilitate testing ofthe bearing insulation.

Proximity probes (with proximitor ortransmitters) and a key phasor areavailable options.

CoolingSystem

Permanent MagnetGenerator (PMG)PMG supplies continuous powerto the exciter through the voltageregulator to maintain up to 300%shortcircuit current from the alterna-tor during a fault condition. It pro-vides full exciter power, regardlessof the alternator voltage. It is alsoa separate voltage source for useoutside of the generator set.

Options & Accessories

6

Automatic VoltageRegulation (AVR)AVR regulates reactive power deliv-ered by the generator to the system.AVR’s regulate voltage in a “droopmode” (default) where voltagedroops from 100% to 95% set pointas load increases from 0% to 100%.This allows paralleled generators toshare reactive power. They also reg-ulate voltage in “cross-current mode”where it is held constant. AVR’s com-municate and exchange “voltageerrors“ utilizing microprocessors witha fast response time and PWM (pulsewidth modulation) power stage.These communications come in fourregulating modes with a bumplesstransfer between modes:

• AVR (automatic voltage regulation)

• PF (power factor) regulation

• VAR (reactive power) regulation

• Field Current (manual mode) regulation Voltage Soft-start Build up

Other functions of the AVR include:

• Voltage Soft-start Build up

• Prevention of generator operation during a continuous overload

• Sequence of Events Recording & Oscillography which is useful during commissioning diagnostics

Neutral GroundResistor (NGR)The NGR acts to limit generator faultcurrent to a low level when a phase-to-ground fault occurs. It also servesto protect the generator from exces-sively high magnetic stresses andtemperatures caused by high faultcurrents. The NGR is time-rated.

AVR

EXCITERARMATURE

BRUSHLESSEXCITER

SYNCHRONOUSGENERATOR

ROTORFIELD

STATORWINDINGS

CT

PT

GCBSYSTEM

BUS

NGR

1000A

EXCITERFIELD

OINTNPUT

AUTOMATIC VOLTAGE REGULATOR(DECS UNIT OR EQUIVALENT)

CT

PT

FIELDOUTPUT

PMGPOWER IN

IDC

(3A

to 1

5A)

DIODERECTIFIER

10 or 30

0 8

EXE

PERMANENT MAGNET

GENERATOREXCITER

FIELD(PERM. MAGNET)

PMGARMATURE

10 or 30

CT1 (1)NEUTRALCURRENT

13,800:120/240 V10A/10 sec

50/5A, C10HEATER

RS

Accessories

• Partial Discharge Sensor Kits

• Air RTD (Resistance Temperature Detectors)

• Space Heaters 50/60 Hz,up to 550 volts

• Large Oversized Fabricated Steel Main Terminal Box - Frame Mounted

• Fabricated Steel Neutral Terminal Box - Frame Mounted

• Surge Arrestors and/or Surge Capacitors

• Current and Potential Transformers

• Vibration monitoring equipment

• Water leakage detector

• Couplings

• Every machine is equipped with Resistance Temperature Detectors (RTD) to monitor stator winding temperature.

• Generator control andprotection panel - optional

• Medium voltage switchgear - optional

Custom conduit box complete with lightningarresters, surge capacitors and currenttransformers.

GE MotorsRod. SP101 Campinas-Monte Mor, Km 3.8

CEP 13-64-654 Campinas SP BrazilTel: 55 (19) 8122 5598 / 2102 8520

55 (11) 8224 3365

www.gemotors.com.br

8 2008 General Electric Company All Rights Reserved.GE and g are trademarks of General Electric Company.

DEA-M1050 0808

The Right ChoicePower Solutions TeamExperienced application engineers are available to solve your toughestgenerator system problems.

Installation, Start-up & Commissioning• Experienced engineers/technicians

available to support site erection, installation and commisioning.

• Long term service agreements including remote monitoring and maintenance assistance.

• Parts center support your local needs and assure your up-time requirements.

• Permanent Short Circuit TestUp to 130% of rated stator current

• No Load Saturation Test Up to 125% of rated stator volts

Testing

Test CapabilityGE Motors has world-class onsite testfacilities. Extensive experience in theperformance of rotating machinerywith all forms of fixed and variablespeed drives has been accumulated.

Each machine is tested at the factorybefore shipment for installation in thefield, thus reducing set-up time

• In-Process TestingRotor impedance; surge test; AC dielectric tests, prior VPI

• Running Tests According to International Standards:NEMA MG1/IEEE 115, IEC 60034-1 & 60034-2 or ABNT 5052

• Short Circuit Ratio (SCR) – from test data

• Mechanical Run Including vibration analyses using velometers and displacement sensors “shaft probes”; dynamic balancing and probe track run out

• Efficiency – Losses segregation method

• Insulation & Polarization Index

• Dielectric Tests In the stator, rotor and brushless

• Over Speed Test Up to 120 % of rated speed

• Lubricating System Functional Tests