BHARAT HEAVY ELECTRICALS LIMITED RANIPUR, HARIDWAR (UTTARAKHAND)

A Project Report On:-

“MANUFACTURING PROCESS OF 500 MW TG STATOR WINDING BAR”

Submitted by Tushar shuklaABES Enginneeing College

ACKNOWLEDGEMENT

My sincere thanks goes to Sh. A.K. Dhiman for his prodigious guidance, precaution, painstaking, attitude reformative and suggestion throughout my summer training schedule.

Special thanks goes all who helped me a lot in giving minute details of the “Manufacturing Process Of 500 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”

Tushar ShuklaB.Tech 3rd year

ABES engineering college

PREFACE

In the light of practical aspects of training for engineering. I am a student of B.Tech. final 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 with practical 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” had been 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 have excited enough in the report of my training.

CONTENTS:-

CHAPTER I - COMPANY PROFILE.

CHAPTER II - ABOUT BHEL, HARIDWAR.

CHAPTER III - BLOCKS IN BHEL, HARIDWAR.

CHAPTER IV - BHEL - AN OVERVIEW

CHAPTER V - BLOCK DIAGRAM OF BLOCK-4.

CHAPTER VI - BRIEF SUMMARY OF CIM SHOP (BLOCK-4)

CHAPTER VII - MFG. PROCESS FLOW CHART OF 500 MW TG STATOR BAR.

CHAPTER VIII- MANUFACTURING PROCESS OF 500 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 BHEL’s 14 manufacturing divisions, 9 service centers & 4 power global players.

Power sector comprises thermal, nuclear, gas & hydro power plant business today, 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 possess 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 has been introduced to acheve higher plant efficencies. 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, capacitor and insulator etc series and shunt compensation system have been also developed and introduced to minimize transmission losses.

TRANSPORTATION:-

A high percentage of trains operated by Indian Railway are equipped with BHEL’s 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 operations:-

BHEL’s 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 motable 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. In Cyprus, 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 HARIDWAR

At 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 and integrated engg. Complex consisting of several plants in INDIA, where about 70000 workers are busy in design and manufacturing of heavy electrical equipment.

At present 70% of the country electrical equipment is generated BHEL HARIDWAR.

PRODUCT’s OF BHEL

Heaps product & capacity ratings

PRODUCT CAPACITY RATING

1. Thermal/nuclear set 210 MW – 1000 MW 2. Hydro set 115 MW 3. Generator Acc. To Requirement 4. Gas turbine 60 MW – 200 MW 5. Heat exchangers, condenser Up to 800 MW 6. AC/DC electrical machine 5 KW – 2000 KW

(a) - AC ( 250 KW – 1600 KW)(b) - DC ( 7KW – 1000 KW)

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CHAPTER - III

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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CHAPTER – IV

BHEL- 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, Defence etc. The wide network of

BHEL’s 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 suaitable products, systems and

services- efficiently and at competitive prices.

BHEL has attained ISO 9001 certification for quality management and all

the manufacturing 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.

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 these sets 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 introduce 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 - VI

BRIEF SUMMARY OF CIM SHOP

(BLOCK – IV)

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 is Bottom part of coil 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 cooie^ generator of te

comparison 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 - VII

MFG. PROCESS FLOW CHART OF 500

MW 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 macnine.

20. Impregnation an curing of bar insulation.

21. Surface finishing of stator bar.

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.

Class – Y upto 90 C

Class – A upto 105 C

Class – E upto 120 C

Class – B upto 130 C

Class – F upto 150 C

Class – H upto 180 C

Class – C >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, and 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

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 in the resin is 5-7% and insulating material isprepared 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 - VIII

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

preinsulated 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 - 20Upper Bar :

U – 10050 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 thecomb 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 carriedout. This process is repeated

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

half. 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 also hollow conductor are used to effect colling 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.(300 A/C supply)

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 etectricalconnection 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 (30°C) 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.

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 vaccum 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 the surface 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.

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 industrial organization is the measure hindrances in the student employment.

In the open economy era of fast modernization and tough competition, technical institutes should 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 in depth 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

STATOR WINDING SECTION IN BLOCK-

I