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INDUSTRIAL TRAINING REPORT

ON

600 MW STATOR BAR MANUFACURING IN BHEL

Submitted in partial fulfillment of the requirement for the award of degree of

Bachelor of Technology

In

ELECTRICAL & ELECTRONICS ENGINEERING

Submitted By

ANKIT CHAUDHARY

Submitted To

Mr. AMIT KUMAR

(Asst. Professor)

DEPARTMENT OF ELECTRICAL ENGINEERINGCOLLEGE OF ENGINEERING ROORKEE,

ROORKEE -247667

(AFFILIATED TO UTTARAKHAND TECHNICAL UNIVERSITY, DEHRADUN)

SESSION: 2012-13

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ACKNOWLEDGEMENT

My sincere thanks goes to Sh. A.K. Dhiman (Sr. Engineer) for his prodigious

guidance, precaution, painstaking, attitude reformative and suggestion throughout my

summer training schedule.

Special thanks goes to Smt. G.D. Mehta who helped me a lot in giving minute

details of the Manufacturing Process of 600 MW TG Stator Winding Bars and

enlightened me with the knowledge of essential equipments and their working.

Last but not the least, my sincere thanks to all the staff members of BLOCK-4,

BHEL, RANIPUR, HARIDWAR

Ankit Chaudhary

B-Tech 4th

YearCollege of Engineering Roorkee,

Roorkee

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PREFACE

In the light of practical aspects of training for engineering. I am a student of B.Tech. third

year had been completed my practical training at BHARAT HEAVY ELECTRICALS

LIMITED (BHEL) HARIDWAR for 30 days.

The objects of training in engineering couse is to correlate the theory withpractical aspects and to make students familiar with the difficulties arises during practical

application so that they can face challenges boldly while working in the field.

As I am a student of electrical engineering so training at BHEL hadbeen particularly beneficial for me. I observe various electrical machineries that are used

in different large scale or a small scale industries and different types of power plants.

BHEL is very large industry for making the different types of equipments

as well as mechanical equipments.

I tried my best to get acquitted with over all plants. I hope that I haveexcited enough in the report of my training.

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CONTENTS:-

CHAPTER I -> COMPANY PROFILE.

CHAPTER II -> ABOUT BHEL, HARIDWAR.CHAPTER III -> BLOCKS IN BHEL, HARIDWAR.

CHAPTER IV -> BLOCK DIAGRAM OF BLOCK-4

CHAPTER V -> BRIEF SUMMARY OF CIM SHOP(BLOCK-4)

CHAPTER VI -> MFG. PROCESS FLOW CHART OF500 MW TG STATOR BAR.

CHAPTER VII -> MANUFACTURING PROCESS OF500 MW TG STATOR WINDING

BARS.

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CHAPTER - I

COMPANY PROFILE

The first plant of what is today known as BHEL was established nearly 40 years

ago at BHOPAL and was genius of heavy electrical equipment industry in India. BHEL

is today the largest engineering enterprise of its kind in India with well recognized track

records of performance making profits continuously since 1971-72 it achieved a sales

turnover of 1023 crore in 1977-78. BHEL caters to core sectors of the Indian economy in

power, industry, transportation, defense etc.The wide network of BHELs 14 manufacturing divisions, 9 service centers & 4

power global players.

Power sector comprises thermal, nuclear, gas & hydro power plant businesstoday, BHEL supplied sets account for nearly 56, 318 MW or 65% of the total installed

capacity of 86, 636 MW in as against nit till 1969-70.

BHEL has proven turnkey capabilities for executing power projectors from

concept to commissioning. It possesses the technology and capability to produce thermal

power plant equipments up to 1000 MW rating and gas turbine generator sets up to a unit

rating of 240 MW. Cogeneration and combines cycle plants have been introduced to

achieve higher plant efficiencies. To make efficient use of the higher ash content coil

manufacturers 235 MW nuclear turbine generator sets and has commenced production of

500 MW nuclear turbine generator head discharge combinations are also engineered and

manufactured is also competitive.

TRANSMISSION:-

BHEL also supplies a wide range of transmission products and system up to 400 KV

class. These include high voltage power and distribution transformer, instrument

transformers, instrument, transformers, dry type transformers. SF6 switch gear, capacitorand insulator etc series and shunt compensation system have been also developed and

introduced to minimize transmission losses.

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TRANSPORTATION:-

A high percentage of trains operated by Indian Railway are equipped with BHELs

traction and traction control equipments including the metro at Calcutta and Delhi. The

company supplies broad gauge.

Electrical locomotive to Indian railway and diesel shunting locomotives to various

industries 5000/6000 hp ac/dc locomotive developed and manufactured by BHEL have

been leased to Indian railway, battery powered road.

INTERNATIONAL OPERATION:-

BHELs product series and projects have been exported to over so countries ranging from

UNITED STATES in the west to NEW ZEALAND in for east INDIA is over 3000 MW.

A few notable ones are 150 MW gas turbine to GERMANY, utility boiler and open cycle

gas turbine plant to MALAYSIA, Tripoli west, power station in Libya and Turkey. InCyprus, hydro generator to New Zealand and hydro power plant to Thailand , Saudi

Arabia, Oman , Greece and Egypt.

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CHAPTER - II

ABOUT BHEL HARIDWARAt the foothills of the majestic Himalayas on the bank of the holy Ganges in Ranipur near

HARIDWAR is located Heavy Electrical Equipment Plant (HEEP) of BHEL.

BHEL, wholly owned by the govt. of INDIA is an integrated engineering complex

consisting of several plants in INDIA, where about 70000 workers are busy in design andmanufacturing of heavy electrical equipment.

At present 70% of the countrys electrical equipment is generated at BHELHARIDWAR.

PRODUCTs OF BHEL

Heaps product & capacity ratings

PRODUCT CAPACITY RATING

1. Thermal/nuclear set 210 MW1000 MW

2. Hydro set 115 MW3. Generator Acc. To Requirement

4. Gas turbine 60 MW200 MW

5. Heat exchangers, condenser Up to 800 MW6. AC/DC electrical machine 5 KW2000 KW

(a) - AC ( 250 KW1600 KW)

(b) - DC ( 7KW1000 KW)

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CHAPTERIII

BLOCKS IN BHEL

Block-1 -> Hydro & turbo generators, AC/DC machines

Block-2 -> Fabrication (steam, hydro & gas turbine)

Block-3 -> Gas, hydro & steam turbine

Block-4 -> CIM

Block-5 -> Heat exchangers, forging & fabrication

Block-6 -> Electrical repair & maintenance of motor & transformer

Block-7 -> Wooden packing works

Block-8 -> Fabrication, seamless tuber and heat exchanges

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CHAPTERIVBHEL- AN OVERVIEW

BHEL is the largest engineering and manufacturing enterprise in India in the energy

related / infrastructure sector. BHEL was established more than 40 years ago,

ushering in the indigenous Heavy Electrical Equipment industry in India, a dream

which has been more than released with a well-recognized track record of

performance. It has been earning profits continuously since 1971-72 and achieved a

sales turnover of Rs. 18,739 crore with a profit before tax of Rs. 3,736 crore in 2006-

07.

BHEL caters to core sectors of the India economy viz. Power Generation and

Transmission, Renewable Energy, Defense etc. The wide network of BHELs 14

manufacturing divisions, 4 power sector regional centers, 8 service centers, 15

regional offices and a large number of Projects sites spread all over India and abroad

enables the company to promptly serve its customer and provide them with suitable

products, systems and services- efficiently and at competitive prices.

BHEL has attained ISO 9001 certification for quality management and all themanufacturing units/divisions of BHEL have been upgraded to the latest ISO

9001:2000 version. All the major units/divisions of BHEL have been awarded ISO

14001 certification for Environmental Management System and OHSAS-18001

certification for Occupational Health and Safety management System. BHEL become

the first Public Sector Company in the country to win the coveted PRIZE for its

Haridwar unit under the CII Exim Award for business excellence as per the globally

recognized model of European Foundation for Quality Management. BHEL is the

only PSU among the 12 Indian Companies to figure in Forbes Asia Fabulous 50

list. It has also won the Business Standard Star Public Sector Company Award

2006. The company received MoU Excellence Award for 2004-2005 and Merit

Certificate for MoU Excellence for 2005-2006.

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Power Generation

Power generation Sector comprises Thermal, Gas, Hydrogen Nuclear power plant

business. As of 31.3.2007. BHEL supplied sets accounts for 80,781 MW or nearly

65% of the total install capacity of 1,25,414 MW in the country. Significantly thesesets contribute 73% of the total power generated in the county.

BHEL has proven turnkey capabilities for executing power projects from Concept to

Commissioning. It possesses the technology and capability to produce Thermal sets

with super critical parameters upto 1000MW unit rating and gas turbine generator sets

of upto 300MW units rating. Co-generating and Combined cycle plants have been

introduced to achieve higher plant efficiencies. To make efficient use of the high-ash-

content coal available in India. BHEL also supplies circulating Fluidized Bed

Combustion (CFBC) boilers for Thermal plants.

The company has proven expertise in Plant Performance Improvement through

Renovation, Modernization and Uprating of a variety of Power plant equipment,

besides specialized know-how of residual life assessment health diagnostics and life

extension of plants. Overall, BHEL built Thermal sets achieved the highest ever PLF

of 78.3% in 2006-2007 which is 1.5% higher than the National average. The

combined operating availability of these sets was 84.7%.

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CHAPTER - V

BRIEF SUMMARY OF CIM SHOP (BLOCKIV)

BAY-1: Bar winding shop: Manufacturing of stator winding bars of generator

BAY-II: 1-Manufacturing of motor stator coil: DC armature coil, main pole coil, inter-

pole coil, equalizer coil etc.

2- Also manufactured heavy duty generator stator bars with New CNC M/c No, 3-464 i.e.

Robol bar centre.

BAY-III: Insulation detail shop; Manufacturing of hard insulation & machining of hares

insulation part (Glass textolite) such as packing, washer, insulation box. wedges etc.

Bar Shop: This shop is meant for manufacturing of stator winding coils of generator that

may be turbo-generator or hydro-generator.

Why do we call it bar: It is quite difficult (rather impossible) to manufacture, handle and

wind the coil in stator slot of generator of higher generation capacity because of its bigger

size and heavy weight. That is why we make coil in two parts. One part isBottom part ofcoil called bottom or tower bar and other part of coil is called top bar or upper bar.

HG Bars: The manufacturing of bars of different capacity as required by the customer

depends upon the water head available at site. The Hydro generator is air cooled

generator compared to its tagger diameter.

(Note:- The manufacturing of Hydro Gen Stator Bars has been shifted from BHEL

Haridwar to BHEL Bhopal to since 2008.

TURBO-GENERATORS: The manufacturing of bars of standared capacity such as:

100MW, 130MW, 150Mw, 210/235MW.

The plant has capacity and technology to manufacture 800MW and 1000MW generators.

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CHAPTER - VI

MFG. PROCESS FLOW CHART OF 500MW TG STATOR BAR

1. Conductor Draw from Store.2. Conductor cutting and end cleaning.3. Transposition of conductor.4. Assembly of all conductors to be used in stator Bars.5. Cross over insulation.6.

Consolidation if slot portion of Bar.

7. IS Test(i.e. inter strand test).8. Forming or Bar (to shape overhang portion).9. Pickling of bar ends (1)10 Mounting of Contact sleeve & bottom part of water box.

11. Brazing of Contact sleeve & bottom part of water box.

12. Pickling of bar ends (2)

13. Mounting of water box leak test.

14. Repickling.

15. Water flow and N2 test.

16. Thermal Shock Application.

17. Helium Leak Test.

18. Reforming of Bar.(i.e. overhang portion).

19. Insulation of bar on CNC machine.

20. Impregnation an curing of bar insulation.

21. Surface finishing of stator bar.

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22. OCP on stator Bar.

23. Preparation of bar for HV and TanQ Test.

24. If O.K. Dispatch to Bicck-1 for laying in the generator.

INSULATION CLASSIFICATION:

Thermal classification of insulation depends upon the temperature

Withstand capability of the insulation.

ClassY upto 90 C

ClassA upto 105 C

ClassE upto 120 C

ClassB upto 130 C

ClassF upto 150 C

ClassH upto 180 C

ClassC >180 C upto 220 C.

TYPES OF GENERATORS:

The generator may be classified based upon the cooling system used in the generators

such as-THRI, TARI, THDI, THDD, THDF, THFF, THW.

T-> First alphabet signifies the type of generator i.e. turbo-

generator or Hydro-generator.

H/A-> Second alphabet stands for the coding media used for

the cooling of rotor i.e. hydrogen gas or air.

R/D/F/I-> Third alphabet signifies the type of cooling or rotor

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eg. Radial,indirect, forced, direct etc.

I/D/F-> Last alphabet stands for the type of cooling of stator

e.g. indirect cooling, direct cooling, forced cooling.

W-> Cooling media used for cooling of stator coil e.g. water.

Resin system:

a) Rich Resin or Thermoreactive insulation system: In this type of insulation system

the bond content in resin 36-37%. The raw materials are ready to use and require

preservation and working on temperature 20-25':C. Its sheif life is one year when kept at

temperature 20 C which could be increased when kept at temperature of 5 C.

b) Poor resin or Micalastic insulation system: In this type of insulation the bond

content inthe resin is 5-7% and insulating material is prepared with accelerator treatment.

The temperature control need not required. The insulating material is applied on job and

then the same is impregnated (fully dipped) in the resin.

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CHAPTER - VII

MANUFACTURING PROCESS OF BARS:

Some Points of Manufacturing Process are in brief as below: ---

1.Conductor Cutting :

This process is done by automatic CNC machine. In this process the reinsulated copper

conductor is cut into number of required length. Insulation is removed from both ends of

the conductor cut.

Lower Bar :

Conductor size 8*4.6*1.5 mm (Hollow)

8*2.8 mm (Solid)

L - 10200 mm c- 500 mm

Conductor No. In 1 Bar Hollow - 20

Solid - 20

Upper Bar :

U10050 mm c- 5 mm

Conductor size 8*4.6*1.5 mm (Hollow)

8*1.3 mm (Solid)

Conductor No. in 1 Bar Hollow - 20

Solid - 40

2. Transposition:Transposition means changing/shifting of position of each conductor in active core (slot)

part. After cutting the required number of conductors, the conductors are arranged on the

comb in staggered manner and then bends are given to the conductors with the help of

bending die at required distance. Then the conductors are taken out from the comb and

die and placed with their ends in a line and transposition is carried out. This process is

repeated for making another half of the bar which would be mirror image of the first half.

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The two halves of the bar are overlapped over each other and a spacer is placed between

the two -halves.

1. To reduce eddy current losses.2. Equalize the voltage generator3.

To minimize skin effect of ac current so small cross section of conductor is used and alsohollow conductor are used to effect cooling by D.M. water

3. Crossover Insulation :

The pre insulation of the copper conductor may get damaged due to mechanical bending

in die during transposition, hence the insulatingspacers are provided at the crossover

portion of the conductors. A filler material (insulating putty or moulding micanite)is

provided along the height of the bar to maintain the rectangular shape and to cover the

difference of level of conductors.

To eliminate inter turn short at bends during edges wise bending and leveling of bars in

slots portion for proper stack pressing.

4. Stack Consolidation :The core part of the bar stack is pressed in press (closed box) under pressure (varies from

product to product) and temperature of 160 C for a given period. The consolidated stack

is withdrawn from the press and the dimensions are checked.

5. Inter Strand Short Test :

The consolidated oar stack is tested for the short between any two conductors in the bar,

if found then it has to be rectified.

This is done to ensure that no local current is flowing due to short circuit between conductors.(300A/C supply)

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6. Forming :

The straight bar stack is formed as per overhang profile (as per design), The overhang

portion is consolidated after forming.

7. Brazing of coil lugs :

For water cooled generator bars, the electrical connection contact and water box for inlet

and outlet of water are brazed.

8. Nitrogen Leak Test :The bar is tested for water flow test, nitrogen leak test and pressure test for given

duration.

9. Thermal shock test:The cycles of hot (80C) and cold (30C) water are flew through the bar to ensure the

thermal expansion and contraction of the joints.

10. Helium leakage test:After thermal shock test bar is tested for any leakage with the help of helium gas.

11. Insulation:The bar is insulated with the given number of layers to build the wall thickness of

insulation subjected to the generating voltage of the machine.

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12. Impregnation and baking:

a) Thermoreactive system: In case of rich resin insulation the bar is pressed in closed

box in heated condition and baked under pressure and temperature as per requirement for

a given period.

b) Micalastic system: In case of poor resin system the insulated bars are heated under

vacuum and the impregnated (dipped) in heated resin so that all the air gaps are filled,

layer by layer, with resin. Then extra resin is drained out and bars are heated and baked

under pressed condition in closed box fixture.

VPI Micalastic system: The bars already laid in closed fixture and full fixture is

impregnated (dipped) in resin and then fixture with box is baked under given temperature

for given duration.

VIP Micalstic system: The individual (separate) bar is heated in vaccum and

impregnated in resin. Then bar is taken out and pressed in closed box fixture and then

baked at given temperature for given duration.

13. Finishing:

The baked and dimensionally correct bars are sanded-off to smoothen the edges and thesurface is calibrated, if required, for the dimension.

14. Conducting varnish coating:

i) OCP (Outer Corona Protection) coating: The black semi-conducting varnish coating

is applied on the bar surface on the core length.

ii) ECP (End Corona Protection) coating: The grey semi-conducting varnish is applied

at the bend outside core end of bars in gradient to prevent from discharge and minimize

the end corona.

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15. Testing:

a) Tan@ test: This test is carried out to ensure the healthiness of dielectric (Insulation)

i.e. dense or rare and measured the capacitance loss.

b) H.V. Test: Each bar is tested momentary at high voltage increased gradually to three

times higher than rated voltage.

16. Dispatched for Winding :

The bars preserved with polythene sleeves to protect from dust, dirt, oil, rain etc are send

to Block-I (Electric Machines Production Block I, Turbo Generators and Hydro

Generators) for winding.

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CONCLUSION

Engineering students will have to serve in the public and private sector industries,

laboratories and workshops based training & teaching in classroom has its own limitations.The lack of exposure to real life, materials processes and functioning of industrialorganization is the measure hindrances in the student employment.

In the open economy era of fast modernization and tough competition, technical institutesshould procedure pass outs as near to job function as possible.

Practical training is one major step in this direction. This training helped me in gaining indepth knowledge of the working of a telephone exchange.

At last I would only say that this training was helpful for my future prospects.

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MANUFACTURING OF BAR IN BLOCK -IV

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STATOR WINDING SECTION IN BLOCK-I