A Report on industrial training at

“BHARAT HEAVY ELECTRICALS LIMITED”Haridwar, India.

Manufacture and assembly of Turbo Generators and Exciter motors

Under the able guidance of

Sh. P.S. Jangpangi (Sr. DGM) – Block 1

Submitted by

Utsav GoyalB. Tech 4th year

Department of Electrical & Electronics EngineeringNaraina College of Engineering & Technology, Kanpur

Uttar Pradesh, India

ACKNOWLEDGEMENT

Practical knowledge means the visualization of the knowledge, which we read in our books. For this, we perform experiments and get observations. Practical knowledge is very important in every field. One must be familiar with the problems related to that field so that he may solve them and become a successful person.

After achieving the proper goal in life, an engineer has to enter in professional life. According to this life, he has to serve an industry, may be public or private sector or self-own. For the efficient work in the field, he must be well aware of the practical knowledge as well as theoretical knowledge.

To be a good engineer, one must be aware of the industrial environment and must know about management, working in such a industry, labor problems etc., so that he can tackle them successfully.

Due to all the above reasons and to bridge the gap between theory and practical, our engineering curriculum provides a practical training of 30 days. During this period, a student works in the industry and gets all type of experience and knowledge about the working and maintenance of various types of machinery. I have undergone my 30 days training (after VI Semester) at BHARAT HEAVY ELECTRICALS LIMITED. This report is based on the knowledge, which I acquired during my 30 days training period at the plant.

UTSAV GOYAL

INDEX

S.No.

01. INTRODUCTION

02. BHEL-A Brief Profile

03. BHEL - AN OVERVIEW

04. HEEP: AN OVERVIEW

05. BRIEF SUMMARY OF THE BAR SHOP

06. TYPES OF TURBOGENERATORS

07. MATERIAL CHECKING

08. CONDUCTOR CUTTING AND END CLEANING

09. TRANSPOSITION OF CONDUCTORS

10. CROSSOVER INSULATION

11. PRESSING

12. ISS- TEST

13. FORMING OF BAR

14. ZERO PICKLING OF BAR END

15. COIL LUG MOUNTING

16. MAIN BRAZING

17. CONDUCTOR CUTTING, DEBBERING AND FACE MILLING

`18. FIRST PICKLING

19 BRAZING OF TOP PART

20. WATER FLOW TEST

21. NITROGEN LEAK TEST

22 THERMAL SHOCK TEST

23 HELIUM LEAKAGE TEST

24. INSULATION

25. IMPREGNATION AND BAKING

26. FINISHING

27. CONDUCTING VARNISH COATING

28. TESTING

28.1 TAN-DELTA TEST

28.2 HIGH VOLTAGE TEST

29. DISPATCHED FOR WINDING

30. MOTOR WINDING

31. CONCLUSION

INTRODUCTION

In 1956, India took a major step towards the establishment of its heavy engineering industry when Bharat Heavy Electrical Ltd., the first heavy electrical manufacturing unit of the country was setup at Bhopal. It progressed rapidly and three more factories went into production in 1965. The main aim of establishing BHEL was to meet the growing power requirement of the country.

B.H.E.L appeared on the power map of India in 1969 when the first unit supplied by it was commissioned at the Basin Bridge Thermal Power Station in Tamil Nadu. Within a decade, BHEL had commissioned the 100 unit at Santaldih. West Bengal. BHEL had taken India from a near total dependence on imports to complete self-reliance in this vital area of power plant equipment BHEL has supplied 97% of the power generating equipment. BHEL has already supplied generating equipment to various utilities capable of generating over 18000 MW power. Today BHEL can produce annually; equipment capable of generating 6000MW. This will grow further to enable BHEL to meet all of India’s projected power equipment requirement. As well as sizeable portion of export targets.

Probably the most significant aspect of BHEL’s growth has been it’sdiversification. The constant reorientation of the organization to meet the varied needs in time with time a philosophy that has led to the development of a total capability from concepts to commissioning not only in the field of energy but also in industry and transportation.

In the world power scene, BHEL ranks among the top ten manufactures of power plant equipment and in terms of the spectrum of products and services offered, it is right on top. BHEL’s technological excellence and turnkey capabilities have won it worldwide recognition. Over 40 countries in the world over have placed orders with BHEL

covering individual equipment to complete power stations on a turnkey basis.

In 1978-79 export earnings reached Rs. 122 crores, the highest for any one-year. BHEL has its headquarters at New Delhi. Its operations are spread over 11 manufacturing plants and number of engineering and service divisions located across the country/ the service divisions includes a network of regional branch offices throughout India.

BHEL-A Brief Profile

BHEL is the largest engineering and manufacturing enterprise in India in the energy-related / infrastructure sector, today. BHEL is ushering in the indigenous Heavy Electrical Equipment industry in India-a dream that has been more than realized with a well-recognized track record of Performa

A widespread network comprising of 14 manufacturing companies, which have international recognition for its commitment towards quality. With an export presence in more than 60 countries, BHEL is truly India’s ambassador to the world. BHEL’s vision is to become world class engineering enterprise, committed to enhancing stakeholder value.

BHEL has:-

Installed equipment for over 90,000MW of power

generation for Utilities, captive and Industrial users.

Supplied over 25000 Motors with Drive Control System to power

projects, Petrochemicals Refineries, Steel, Aluminum, Fertilizer,

Cement plant, etc.

Supplied Traction electrics and AC/DC locos over

12000 kms Railway network.

Supplied over one million Values to Power Plants and other

Industries

BHEL - AN OVERVIEW

The first plant of what is today known as BHEL was established nearly 40 years ago at Bhopal & was the genesis of the Heavy Electrical Equipment industry in India.

BHEL is today the largest Engineering Enterprise of its kind in India with excellent track record of performance, making profits continuously since 1971-72.

BHEL business operations cater to core sectors of the Indian Economy like.

Power

Industry

Transportation

Transmission

Defenses etc.

Today BHEL has

14 Manufacturing Divisions

9 Service Centers

4 Power Sector Regional Centers

150 Project sites

BHEL’s vision is to become world -class engineering enterprise, committed to enhancing stakeholder value. The greatest strength of BHEL is its highly skilled and committed 44,000 employees.

Spread all over India & abroad to provide prompt and effective service to customers.

BUSINESS SECTOR

BHEL operations are organized around business sectors to provide a strong market orientation. These business sectors are Power Indus and International operations.

POWER SECTOR

Power sector comprises of thermal, nuclear, gas and hydro business. Today BHEL supplied sets account for nearly 65% of the total installed capacity in the country as against nil till 1969-70.

BHEL has proven turnkey capabilities for executing power projects from concept to commissioning and manufactures boilers, thermal turbine generator set and auxiliaries up to 500MW.

It possesses the technology and capability to procure thermal power generation equipment up to 1000MW.

Co-generation and combined cycle plants have also been introduced.

For efficient use of the high ash content coal-BHEL supplies circulating fluidized boiler.

BHEL manufactures 235MW nuclear sets and has also commenced production of 500MW nuclear set.

Custom-made huge hydro sets of Francis, Elton and Kaplan types for different head- discharge combinations are also engineered and manufactured by BHEL.

INDUSTRY SECTOR

BHEL is a major contributor of equipment and system to important industries like

Cement

Petrochemicals

Fertilizers

Steel paper

Refineries

Mining and Telecommunication

The range of system and equipment supplied including captive power stations

High speed industrial drive turbines

Industrial boilers and auxiliaries

Waste heat recovery boilers

Gas turbines pump, valves, seamless steel tubes

Heat exchangers

Process control etc.

TRANSPORATION :-

BHEL supplies a wide equipment and system to Indian Railways.

Electric locomotive

Traction electric and traction control equipment

TELECOMMUNICATION:-

BHEL also caters to Telecommunication sector by way of small, medium and large switching system.

BHEL has been divided into many blocks:-

1). Block-1:- In block one turbo generator, generator, exciter motors

(A.C&D.C) are manufactured & assembled

2). Block-2:- In block two large size fabricated assemblies\component for power

equipment are manufactured & assembled.

3) Block-3:- In block -3 steam turbine, hydro turbines, and gas turbines,

turbines blade are manufactured & assembled

4) Block-4:- In block -4winding for turbo generator, hydro generator, insulation

of A.C&D.C motors insulating component for turbo generator, hydro generator motors are manufactured & assembled

5) Block-5:- In block -5 fabricated parts of steam turbine water box, hydro

turbine turbines parts are manufactured & assembled

6) Block-6:- In block -6 fabricated oil tanks hollow guide blades, rings,

stator frames rotor spiders are manufactured & assembled

7) Block-7:-

In block -7all types of dies including stamping dies, stamping for generators &motors are manufactured & assembled

8) Block-8:- In block -8 LP heaters, ejectors, steam coolers, oil coolers, ACG

coolers, oil tanks are manufactured & assembled

MANUFACTURING DIVISIONS

Heavy Electrical Plant, Piplani, Bhopal Electrical Machines Repair Plant (EMRP), Mumbai

Transformer Plant P.O. BHEL, Jhansi.

Bharat Heavy Electrical Limited :

Central Foundry Forge Plant., Ranipur, Hardwar

Heavy Equipment Repair Plant, Varanasi.

Insulator Plant, Jagdishpur, Distt. Sultanpur.

Heavy Power Equipment Plant, Ramachandra Puram, Hyderabad

High Pressure Boiler Plant & Seamless Steel Tube Plant,

Tiruchirappalli.

Boiler Auxiliaries Plant, Indira Gandhi Industrial Complex, Ranipet.

Industrial Valves Plant, Goindwal.

Electronics Division :

Electronics Systems Division.

Amorphous Silicon Solar Cell Plant (ASSCP).

Electro porcelains Division.

HEEP: AN OVERVIEW

Over the years, Bharat Heavy Electrical Limited has emerged as world class engineering and Industrial giant, the best of its kind in entire South East Asia. Its business profile cuts across various sectors of engineering/power utilities and industry. The company today enjoys national and international presence featuring in the " fortune international-500” and is ranked among the top 12 companies of the world, manufacturing power generation equipment. BHEL has now 14 manufacturing division, 8 service centers and 4power power sectors regional centers besides a large number of project sites spread over India and abroad.

The company is embarking upon an ambitious growth path through clear vision, mission and committed values to sustain and augment its image as a world-class enterprise.

VISION

A world-class innovating, competitive and profitable engineering enterprise providing total business solution.

MISSION

To be the leading Indian engineering enterprise providing quality products system and services in the field of energy, transportation, infrastructure and other potential areas.

VALUES

Meeting commitments made to external & internal customers

Foster learning creative and speed of response

Respect for dignity and potential of individual

Loyalty and pride in the company

Team playing

MANUFACTURING PROCESS OF TURBO

GENERATOR & STATOR BAR

BRIEF SUMMARY: ABOUT THE BAR SHOP

This shop is meant for manufacturing of stator winding coils of

generator that may be turbo generator or hydro generator.

HR BARS

Manufacturing of bars of different capacity depends upon the

water head available at site. The hydro generator is air called

generator of lesser length.

TURBO GENERATOR BAR

For the turbo generator the manufacturing of bars of standard

capacity such as 100 MW, 130MW, 150MW, 210/235MW,

210/250MW. This plant has capacity and technology to

manufacturing 800 MW generators.

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 =i.e. Turbo Generator or Hydro Generator.

H/A =i.e. Hydrogen Gas or Air.

R/D/F/I =i.e. Radial, indirect, forced, direct etc.

I/D/F =i.e. Indirect cooling, direct cooling, forced cooling.

W =i.e. cooling media used for cooling of stator coil e.g.

water.

MATERIAL CHECKING

First we check the material of the conductor. And the total

insulation upon the conductor. The width of the copper conductor

should be:

a. For Lower bar = 8 x 2.8mm (Solid)

b. For Upper bar = 8 x 1.3mm (Solid)

c. For Hollow conductor= 8 x 4.6 x 1.5mm (Solid)

CONDUCTOR CUTTING AND END CLEANING

This process is done by the automatic CNC machine, in this

process the length of lower bar & upper bar is decided as

following as per drawing-

Lower Bar

a. Solid conductor length = 10,200mm (10 Plates)

b. Hollow conductor length = 10,200mm (10 Plates)

Upper Bar

a. Solid conductor length = 10,050mm (10 Plates)

b. Hollow conductor length = 10,050mm (10 Plates)

This insulation is removed from both ends after the cutting of conductor

i.e. 500mm for both lower & upper bar.

TRANSPOSITION OF CONDUCTOR

Transposition means changing or shifting of position of each

conductor in active care (slot) part. After cutting the required

number of conductors are arranged on the comb in staggered

manner and than bands are given to the conductor with the help of

bending die at required distance.

Setting of die

a. Comb of setting for lower bar’s

Die 1st Die 2nd Die 3rd

2200.2mm 3735.3mm 6586.2mm

b. Comb of setting for Upper bar’s

Die 1st Die 2nd Die 3rd

2109mm 3620.2mm 6496.2mm

This process is repeated to making another half of the bar.

CROSS OVER INSULATION

Cross over insulation is give to the conductor for the protection in

which the insulating spacer are provided at the cross over portion. In

this insulation the No-max paper is used.

Here the filter material (insulating putty of moulding micanite)

spacer is provided along the high of bar to maintain the rectangular

shape. The size of spacer should be –

1st Band = 146mm

2nd Band = 219mm

3rd Band = 292mm

STACK CONSOLIDATION OR PRESSING

The core part of the bar stack is pressed in press under the pressure

between 70kg to 80kg (various from product to product) and the

temperature between 90 Deg.C to 160 Deg.C for a given period.

Here four bars is pressed in one time and six to eight plates are used

for pressing. After that the consolidated stack is withdrawn from the

press.

INTER STAND SHORT TEST (I.S.S.Test)

In this test first we make the distance to the non insulating portion of

the bar. Here we check the short between any two conductor. After

this test the bars are again go for the second pressing. In which

attached full slot separator between two half bar no-max paper and

tapped with transparent film. In this test if any error is found then it

has to be rectified.

FORMING OF BAR

In this operation the straight bar stack is formed as per overhang

profile. In this process bars should be formed on universal former

and marked for the thermal space. After it they are moved for cutting

of extra conductor.

ZERO PICKLING OF BAR END

Pickling is the process of the cleaning of components by the

chemicals. The pickling solutions are:

a. Water = 100 parts by weight

b. Sulphuric Acid = 10 parts by weight

c. Phosphoric Acid = 5 parts by weight

d. Hydrogen per Oxide = 5 parts by weight

The temperature should be maintain 50 Deg.C to 60 Deg.C. The end

portion of bar is dipping in this solution upto 10 to 15 min.

During this pickling process some aciditic properties are effected to

the end portion of bar. So to neutralization of it dipped the bars again in

the ammonia solution. For the shining of end part the bars are dipped in

ethyal alcohol (C2H5OH) solution and dry with nitrogen Pressure.

COIL LUG MOUNTING

In this process contact sleeve and the bottom part of the water box

are adjust at the give dimensions. The operation of mounting of

contact sleeve and bottom part of water box is complete in following

steps-

a. Check the dimension of contact sleeve and water box bottom part.

b. Stand by bar for setting of lug.

c. Setup to the solid conductor in each row as per drawing.

d. Then insert the contact sleeve upon the solid and hollow conductor

and temporally installed to it. And also installed the bottom part of

water box.

e. Maintain the gap between contact sleeve and bottom part of water

box approx 20mm.

After the lug mounting cutting of extra solid conductor.

MAIN BRAZING

There are the following steps to brazed the lug.

a. Stand by bar of setting for brazing.

b. Then heated the lug point through the two indictor at the temperature

of 700 Deg.C .

c. For brazing use brazing alloy L-Ag-15P by four person. This is the

silver platinum alloy wire of melting point 700 Deg.C to 750 Deg.C.

d. This Temperature is give through the laser rays.

CONDUCTOR CUTTING, FACE MILLING AND DEBBERING

After the main brazing bars is moved for cutting of extra part of

conductors as per drawing. Here cut the end part of the bottom part

of water box and taken for face milling.

In this process the conductor is given the accurate shaped as per the

measurement and it is taken in account that any part of the surface is

not left uneven and dull.

Then in Debbering, the bars edges are many a time left with twigs

and sharp needle type mettle cutting known as bar and this process

of removing is known as Debbering.

FIRST PICKLING

This is the same process of pickling which is done before the lug

mounting or zero pickling. After this pickling process the bar is

moved the brazing of top part of water box in both side.

BRAZING OF TOP PART

Thought the induction process the top part of water box is brazed in

both side.

As per the previous main brazing first we stand by bars of setting for

brazing then we attached the top part from the bottom part of water

box. Then healed the top part by top inductors at the temperature of

400Deg.c.

For this type of brazing use L-Ag-40Cd. This is the alloy silver

academy which have 40% cadmium and the melting point is 400 Deg.C

to 500 Deg.C. This brazing is done for both end.

After the brazing the bars is go for second pickling which is the same

process as previously explain.

WATER FLOW TEST

Thought this test check the flow water equivalently in the hollow

conductor of the bar. There is the following steps of checking-

a. Water should be exit all the total hollow conductor.

b. If some burrs are jammed it should be removed to give very high

pressure of water and clean with the help of solid wire.

c. The main point of testing is that the water flow into the bar and exit

from the water box fall down approximately to cover 1 Mtr. From

each conductor.

NITROGEN LEAK TEST

In this test the bar is tested for leakage into the components of bar. In

this test flow of nitrogen gas with pressure of 10kg/Cm2 to check the

leakage in to the hollow conductor. If leakage found the bar is

rejected.

THERMAL SHOCK TEST

The cycles of hot (80 Deg.C) and cold (30 Deg.C) water are flew

thought the bar to ensure the thermal expansion and contraction of

the joints. The time of low of hot & cold water should be approx 32

to 40min and give the time between to flow of hot & cold water is 5

min. this process is applied atleast 8 hours.

HELIUM LEAKAGE TEST

In this test the bar’s end is tested to flow of helium gas with the

given pressure if the end part of the bar is leakage then the helium

gas is covered the surface of water box and indicator indicate the

point of leakage.

INSULATION

For the insulation sunmika therm tape or sunmika pleese tape is used

which is the combination of mica + glass + varnish. It is used for

corona protection. In this insulation to layer of pleese tape + to layer

of therm tape and after them again to mica pleese tape is used.

Process of Insulation

a. Clean the bar.

b. Clean with chemical or thinner.

c. Taping

d. Realizing film from the mica plastic section.

In insulation the wall thickness of insulation is subjected to the generating

voltage of the machine.

IMPREGNATION AND BAKING

1. 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.

2. Micalastic system: In case of poor resin system the insulated bars

are heated under vaccum and 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

in resin and then fixture with box is baked under given temperature

for the given duration.

VIP Micalastic System

The individual 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.

FINISHING

The baked and dimensionally correct bars are sanded-off to

smoothen the edges and surface calibrated if required for the

dimension.

CONDUCTING VARNISH COATING

OCP (Outer Corona Protection) Coating: The black semi-

conducting varnish coating is applied on the bar surface on the core

length.

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.

TESTING

1. Tan Test: This test is carried out to ensure the healthiness of

dielectric (insulation) i.e. dense or rare and measured the capacitance

loss.

2. H.V. Test: The each bar is tested momentarily at high voltage

increased gradually to three times higher than rated voltage.

DISPATCHED FOR WINDING

If the bar is passed in all the operation and testing after completing

then the bar is send for stator winding.

TURBO GENERATORS

(a) Air Cooled Generators Upto 200 Mw Range (Type: TARI ) Salient Design Features

Stator core and rotor winding direct air-cooled

Indirect cooling of stator winding

Horizontally split casing design of

stator

Vertically side mounted coolers in a

separate housing

Micalastic bar type insulation system

Separately assembled stator core and

winding for reducing the manufacturing cycle

Brushless/static excitation system

(b) Hydrogen Cooled Turbogenerators Of 140-260 Mw Range (Type: THRI ) Salient Design Features

Stator core and rotor winding directly

hydrogen cooled

Indirect cooling of stator winding

Rigid core bar mounting

Micalastic insulation system

End shield mounted bearings

Top ripple springs in stator slots

Ring type shaft seals

Symmetrical ventilation.

MOTOR WINDING

9.1 Technical Requirements

(1) Count the coil groups in the anti clock wise direction locking from the

connection end.

(2) Leads of the coils groups lying on the outer periphery of the overhang

position shall be the finish and those lying on the inner periphery shall be

the start to coil groups.

(3) Leads shall be taken form the coil side lying at inner periphery of slot

No.1.

(4) The coil group No.1 shall Lie at top with its axes coinciding with the

vertical axis of the frame.

(5) Take out terminal leads 02 U2, V2, W2 for left hand side terminal box

and 02 U1, V1, W1 for right hand side terminal box. When looking

form the connection end.

Circuit diagram:-

WINDING DIAGRAM OF MOTOR WINDING

9.2 Winding data

NO. OF PHASE 3

NO. OF POLES 6

PHASE CONNECTION Y

NO. OF PARELLEL PATH 2

NO. OF COIL GROUP 18

9.3 Connection of motor winding

CONCLUSION

The second phase of training has proved to be quite faithful.

It proved an opportunity for encounter with such huge machines like

turbo-generator hydro generator etc.

The architecture of B.H.E.L., the way various units are linked

and the way working of whole plant is controlled make the students

realize that Engineering is not just structural description but greater part

is planning and management. It provides an opportunity to learn tech.

Used at proper place and time can save a lot of labour.

But there are few factors that require special mention. Training

is not carried in true spirit. It is recommended that there should be

projectors especially for trainees where presence of authorities is ensured.

However, training has proved to be satisfactory. It has allowed us an

opportunity to get an exposure of the practical implementation of

theoretical fundamentals.