AN INDUSTRIAL TRAINING ON

“MANUFACTURING OF 600MW STATOR BARS”AT

Presented ByNeeraj Varshney

1216521034Electrical & Electronics Engg.

Introduction to BHEL Key Features of BHEL BHEL mission, vision & values Blocks in BHEL, Haridwar Layout & study of Block 4 Manufacturing of 600MW stator bars Conclusion

Contents

Introduction to

Bharat Heavy Electricals Limited, Haridwar

Key Features of BHEL:-FEATURES DESCRIPTIONINDUSTRY 1. Heavy Electrical Equipment Plant

2. Central Foundry Forge Plant

ESTABLISHED IN 1964HEADQUARTER New Delhi,IndiaAWARDS & RANK 1. Largest PSU with ‘MAHARATNA STATUS’

2. 4th rank in FORBES 50 list3. Quality, Safety, Environmental Management Company

TOTAL TURNOVER 9.07 billion $

PRODUCTS Turbines, Boilers, Generators, Sensors, Drives, Circuit Breakers, Switch Gears, Motor etc.

FEATURES

DESCRIPTION

CERTIFICATIONS 1. ISO 9001:2000 for Quality Management2. ISO 14001 for Environmental Management System3. OHSAS-18001 for Occupational Health & Safety

Management System

CAPACITY 59% in India’s total Installed Generating Capacity.

EMPLOYMENT 49,280

EXPORTS To about 21 countries.

BHEL MISSION,VISION & VALUES :

LOCATION SHOWING THE PLANTS OF B.H.E.L OVER INDIA :

HEADQUARTER MANUFACTURING UNITS CHECK & REPAIRING

UNIT

NEW DELHI

KOLKATAVARANASI

GOINDWAL

HARIDWARRUDRAPUR

JAGDISHPURJHANSI

BHOPAL

HYDERABAD

BANGALORERANIPETTIRUCHIRAPALLY

CHENNAI

BLOCKS IN BHEL,HARIDWAR

BLOCKS DESCRIPTIONBlock -1 Machine block(Turbo generators & Exciter

manufactured )

Block-2 Power equipment manufactured & Assembled

Block-3 Turbine section

Block-4 Coil & insulation manufacturing block

Block-5 Water box & turbine parts

Block-6 Stator frames & rotor blades manufactured

Block-7 Stampings & Dies for motor & generator

Block-8 Coolers & oil tanks

BLOCK-4 BAY-2

BAY-1

BAY-3

Bar Winding Shop

Bars with CNC machines

Insulation Detail Shop

LAYOUT OF BLOCK-4

MANUFACTURING OF 600 MW STATOR BAR : Why we call it bar????

It is difficult to wind a large capacity generator with a specific gauge of Cu conductor or a wire. In large capacity generators we use bunch of Cu conductors is used after pass through a process. Those

Cu strips called as bar. Bar may be 210MW, 500MW, 600MW etc.

PROCEESES INVOLVED:-INSULATION

CHECKCONDUCTOR

CUTTINGTRANSPOSITIO

NSTACK

PRESSING

INTER STRAND SHORT TEST

FORMINGPICKLING PROCESS

BRAZING

WATERTEST

NITROGENTEST

INTERNAL PICKELING

BAROSCOPIC TEST

THERMAL TEST

HELIUM LEAKAGE

TESTINSULATION

IMPREGNATION & BAKING

FINISHING VARNISH & COATING

Insulation check : Insulated Copper conductors are used: (1) Solid Cu conductor (2) Hollow Cu conductor

Conductor cutting : It is done by C.N.C MACHINE. LOWER BAR :

UPPER BAR

CONDUCTOR SIZE LENGTH NO. OF CONDUCTORS

9.5*4.4*1.3mm hollow 11053mm Hollow-14

9.5*1.2mm solid 11053 mm Solid-28

CONDUCTOR SIZE Length NO. OF CONDUCTORS

9.5*4.4*1.3mm (Hollow) 10887mm Hollow – 14

9.5*1.2mm (Solid) 10887mm Solid- 28

Transposition : 1). To reduce eddy current in bar. 2). Done manually

Stack pressing : This is done for hollow & solid conductors to make a one unit.

Bar is pressed both vertically & horizontally. Inter strand short test :

(1) To check the short circuit between conductors. (2) No current flow between the conductors.

Pickling process : BASIC SOLUTION FOR PICKELING PROCESS 1). For cleaning job (oily, dirty and dusty job) and for remove acidic properties.2). Solution is heat upto 50˚ C.3). Then our job is dipped in pickling solution for 15 minutes.

Forming : 1). Done on Universal forming Machine. 2). A bend is given to the bar, both side . 3). Bend use for terminal connections.

SOLUTION NAME PERCENTAGE(%)

SULPHURIC ACID 10%

PHOSPHORIC ACID 5%

HYDROGEN PEROXIDE

5%

Brazing : 1. Brazing is basically the process of fixation of both the contact sleeve and water box bottom part to bar.2. It is done by Induction machine.

Water test : 1. To check any blockage and vent in the bar. 2. Also check the flow of water in the bar.

Nitrogen test : 1. To check any puncture in the bar. 2. If there is any puncture air bubble give us exact location of puncture.

Thermal shock test :1. To check the bar at extreme condition. 2. Process repeated at 26 times.3. 26 hot water & 26 cold water cycle.4. Determines the strength of the bar.

Internal pickling: 1. Done for cleaning of hollow conductors. 2. Used for removing the impurities from

inside.

Helium Leakage Test: 1. Test is done in front of customer 2. By passing the helium inside the bar. 3. It pass at pressure of 11kg/cmsq.

Insulation : 1. To prevent short circuit, insulation is done. 2. MICALASTIC is used as insulating tape

Conductor varnish and Coating (1) ECP(End corona protection) coating

Grey semiconducting varnish is applied at the end of the bars.

(2) OCP(Outer corona protection)coating

Black semiconducting varnish coating is applied at the core length.

FINISHING1. BARS ARE SANDED OFF.2.THE EDGES ARE SMOOTHENED.

Manufactured Bars

Bars used in generator

Conclusion

The training has proved to be useful as well as faithful.

Got a chance to encounter with the generators, its manufacturing units, etc.

Gives an opportunity to learn about the optimization of technology.

It also helped me to have an exposure of the practical implementation of the theoretical knowledge.