Summer Training Project Report

AKNOWLEDGEMENT

I firmly believe that a work of significant proportions cannot be attributed to a single person

or a single effort, its overall success depends upon all those individuals who contributed in

their unique way to the accomplishment of its broader objectives.

I express my deepest and most sincere thanks to Mr. R. K. Kajla, Deputy G.M.-HR for giving

me an opportunity to work on this project and extending support to me during my stint with

HAVELLS INDIA LTD.

I acknowledge my indebtness to Mr S. K. Yadav, for giving me inspiring support, guidance,

valuable suggestions and encouragement throughout this project.

Above all I wish to thank my family for being my constant support and

source of encouragement during the project.

APROVAL FROM GUIDE

This is to certify that Mr. Sumit Bansal student of NATIONAL INSTITUTE OF

TECHNOLOGY, KURUKSHETRA has completed project work on “STUDY ON

ELECTRICAL POWER SYSTEM” under my guidance and supervision.

I certify that this is an original work and has not been copied from any source.

DATE: Signature of Guide

Name of Project Guide

Mr. S. K. Yadav

DECLARATION

I hereby declare that this Project Report entitled “STUDY OF ELECTRICAL POWER

SYSTEM” in HAVELLS INDIA LTD. submitted in the partial fulfillment of the requirement

of B.TECH. of SEEDLING ACADEMY OF DESIGN TECHNOLOGY AND

MANAGEMENT, Jaipur is based on primary & secondary data found by me in various

departments, books, and websites & Collected by me in under guidance of Mr. S. K. Yadav.

DATE: SUMIT BANSAL

B.TECH

MECHANICAL ENGINEERING

N.I.T.K.

CONTENTS

1. Electrical Industry

2. Company’s Profile And History

3. Electric Motor

3.1 History Of A.C. Motor

3.2 Principle

3.3 A.C. Motor

3.4 D.C. Motor

3.5 Universal Motor

4. Electric Generator Or Dynamo

4.1 Historic Development

4.2 Principle

4.3 Jedlik’s Dynamo

4.4 Faraday’s Disk

5. Transformer

5.1 Power Transformer

5.2 Auto-Transformer

5.3 Polyphase Transformer

5.4 Oil Cooled Transformer

5.5 Pulse Transformer

5.6 Audio Transformer

6. Substation(S.L.D.)

Bibliography

ABOUT ELECTRICAL INDUSTRY

The electrical industry contributed and helped reshape the modern technology, powering the

tools and appliances used in daily life.

It all started with Allessandro Volta's development of the battery in 1800 and Joseph Henry's

work on electromagnets, Michael faraday’s invention of the generator in 1830 marked an era

of modern technologies followed with the first commercial application of electricity, the

Telegraph by Samuel F.B. Morse.

The production of arc light with the help of direct current (DC) generator invented by Charles

Brush in 1876 illuminated the 19th century

Thomas Edison, recognizing the desire for electric lighting similar to existing gas lights,

invented in 1879 an Incandescent Lamp that produced light when current passed through a

high resistance filament in a vacuum.

In 1882, Nikola Tesla invented the rotating magnetic field, and pioneered the use of a rotary

field of force to operate machines. He exploited the principle to design a unique two-phase

induction motor in 1883. In 1885, Galileo Ferraris independently researched the concept. In

1888, Ferraris published his research in a paper to the Royal Academy of Sciences in Turin.

Tesla had suggested that the commutators from a machine could be removed and the device

could operate on a rotary field of force. Professor Poeschel, his teacher, stated that would be

akin to building a perpetual motion machine.[11] Tesla would later attain U.S. Patent

0,416,194, Electric Motor (December 1889), which resembles the motor seen in many of

Tesla's photos. This classic alternating current electro-magnetic motor was an induction

motor.

Michail Osipovich Dolivo-Dobrovolsky later invented a three-phase "cage-rotor" in 1890.

By 1890, Edison general electric, the Westinghouse electric and manufacturing company

founded by George Westinghouse, and the Thomson Houston electric company were the key

players. Westinghouse aggressively promoted the use of alternating current (AC), while

Thomson Houston assisted fledgling utilities to fund power stations. AC, which could serve

more customers over a wider area, soon became the industry standard. After Edison GE and

Thomson Houston merged in 1892 to form the general electric company, the new firm

dominated in finance, incandescent lamp manufacture, and the manufacture of steam turbines

to power generators. In 1896, the first hydroelectric power station, at Niagara Falls delivered

abundant electricity to industries demonstrating AC's full potential.

After greatly expanding generating capacity, the electrical industry in the 1920s campaigned

to increase domestic consumption. Many households in this decade acquired electric stoves,

washing machines, irons, radios, and vacuum cleaners.

Seeking lower costs, electrical utilities adopted nuclear reactor technology, predictions were

that electricity would soon be “too cheap to meter” went unfulfilled, however. Nuclear‐power

plants proved not only expensive to build but difficult to manage and prone to dangerous

accidents.

Yet consumer demand for electricity increased as they grew more dependent on reliable

electric power to heat and cool buildings, control machinery, operate appliances and

computers, and supply indoor and outdoor illumination, governments established programs to

promote wind, water, and solar power.

AFTER BEING in the doldrums towards the end of the 1990s, the Indian electrical

equipment industry is seeing a revival in the last couple of years with the growth rate

averaging 7 per cent per annum. The worldwide electric power industry provides a vital

service essential to modern life. It provides the nation with the most prevalent energy form

known in history “electricity”. It advances the nation’s economic growth and productivity;

promotes business development

and expansion; and provides solid employment opportunities to workers globally in general

and India

in particular. It is a robust industry that contributes to the progress and prosperity of our

nation. Today the electric power industry operates in a hybrid model of competition and

regulation. The worldwide electrical and electronics industry is growing at a fast pace which

consist of manufacturers, suppliers, dealers, retailers, electricians, electronic equipment

manufacturers

Power industry restructuring, around the world, has a strong impact on Asian power industry

as well. Indian power industry restructuring with a limited level of competition, since 1991,

has already been introduced at generation level by allowing participation of independent

power producers (IPPs). The new Electricity Act 2003 provides the provision of competition

in several sectors. It is felt that the prevailing conditions in the country are good only for

wholesale competition and not for the retail competition at this moment.

As per the recent surveys, the global electrical & electronics market is worth $1,038.8 billion,

which is forecasted to grow to $ 1,216.8 billion at the end of the year 2008. If we talk of

electrical & electronics production statistics, the industry accounted for $1,025.8 billion in

2006, which is forecasted to reach $ 1,051.5 billion in future.

OUTLOOK OF THE WORLD'S ELECTRICAL &

ELECTRONICS MARKET

Classification 2007 2008

Home Use 116,221 119,201

Industrial Use 730,928 119,201

Information Device 330,834 345,131

Communication Device 248,424 258,307

Office Devices 11,735 258,307

Others 139,935 258,307

Electronics Parts 321,439 338,308

Total 1,168,588 1,216,895

SIZE OF THE ELECTRICAL INDUSTRY

Top three electrical and electronic goods manufacturing countries in the world are: United

States of America, Japan and Korea respectively. The United States of America being the

largest producer of electronic products worldwide contributes the total share of around 21%.

Furthermore, USA is at the forefront to have the largest market share with around 29% in the

Global market.

The World's electrical market size was $1038.8 billion in 2006, since last year an increase of

10.6% is forecasted to grow even more. The industrial electrical goods industry size was

$651.3 billion, contributing around 62.7% of the total. With regard to electronics parts and

components sector, the total market share was around $282.7 billion i.e. 27.2% while home

electronics was $ 104.7 billion. This figure is supposed to increase in this decade.

MAJOR PRODUCTION AND EXPORT CENTERS

As electrical manufacturing industry is growing with a fast pace, Western Europe is

developing gradually to contribute this industry. Western Europe comprising of 16 countries

is contributing around 22% of the global market share. Simultaneously, Eastern Europe is

forecasted to grow about $ 24 billion in 2013 from $ 9 billion in 2006.

If we talk of Asia Pacific region, China, Japan, North & South Korea, Singapore and India

are the top manufacturer of electrical and electronic products. Among these Asian countries,

China is becoming the manufacturing region of electronic products on the globe.

One of the issues often raised is the fear of flood of imports from China. According to Mr.

Krishnakumar, President of the Indian Electrical and Electronics Manufacturers Association

(IEEMA). Chinese electrical products certainly are lower in cost, but their quality is suspect.

For example, Chinese compact fluorescent lamps proved to be a failure in India. The Indian

industry is not afraid of Chinese competition, so long as the products from there are

conforming to quality standards. The Quality Control Order of February 2003, promulgated

by the Govt. of India, has specified that unless a product conforms to the Bureau of Indian

Standards criteria, it cannot be marketed in India. This should go a long way in preventing the

flood of low quality, low price products coming from China.

At persent, Asia is growing with more speed in comparision to Americas and Europe. In

2002, Asia occupied 41% of total electronics market share, which grew upto 56% in 2007.

Those days are not far away when Asia will become the market leader globally.

FUTURE OUTLOOK OF ELECTRICAL INDUSTRY

Today, the electrical industry is experiencing phenomenal and remarkable changes

worldwide. The worldwide electrical industry is distinguished by fast technological advances

and has grown rapidly than most other industries over the past 30 years. Products are heading

towards new destination where cost is less than other place with higher costs involved. These

places offer the most long term potential for market growth. Companies indulged in

manufacturing electrical products are investing a lot on research and development for the best

products to meet the demand of the market. They are manufacturing the product with best

quality at reduced cost due to many competitors.

The domestic market in India is itself large, and one must firstly satisfy this market with

products that meet international quality standards. With increasing globalization, every

international player is now operating in India, providing goods and services complying with

international quality. Once we deliver high quality products and services within the domestic

market, accessing the international market for exports should not pose a serious challenge.

The Electrical/Electronics Industry in India is growing to its full potential in the coming years

and no doubt that India will soon come to be recognized for quality products and services

which in turn, will bring this industry to a position of true leadership.

FACTORS GOVERNING THE GROWTH OF

ELECTRICAL INDUSTRY

Every industry thrives on some supporting factors. In this connection, there are few factors

governing the growth of electrical and electronics industry:

Research & development played an important role to the increased productivity and

higher-value added electrical and electronics products.

Foreign investments accelerated growth in production and export as well. To expand

their business, foreign companies have done huge investment which lead developing

countries in establishing production units.

Global industries like Medical, Telecommunications, Industrial & Automotive

industries have been cordially supported by electrical & electronics industry.

Increase in income changed living standards of the common mass. As a result, it

increased the demand of electronics especially consumer electronics products

globally.

Electric & Electrical industry is highly fragmented which comprises of many small

and medium size enterprises resulting into a huge industry.

Asia Pacific region is emerging as the most spinning place for the consumer

electronics industry, as the markets remain still unbroached.

Innovation has played importantly in this industry. It led to a consistent demand for

newer and faster products and applications

ABOUT HAVELLS

Company History - Havells India

YEAR

1983 - The Company was originally incorporated as Havell's India Private Limited

on 8th August, under the Companies Act, 1956 and subsequently the name was

changed to Havell's India Limited vide Certificate dated 31st March, 1992.

The Company was promoted by S/Shri Qimat Rai Gupta and Surjit Kumar Gupta.

It has facilities for manufacture of switchgear items viz.

Miniature Circuit Breakers (MCB), MCB Distribution Boards (DB) and HRC fuses at

Samepur Badli, Delhi.

The Company also entered into a Technical Collaboration with M/s Christian Geyer

GmbH & Co., Germany for the manufacture of Miniature Circuit Breakers in India.

1989 - The company undertook addition to its tool room facilities by going in for

manufacturing of sheet metal and molding tools in-house.

1991 - The company amalgamated with itself Elymer Havbell's Pvt. Ltd. which had

facilities for manufacture of HRC fuses with an installed capacity of 2,50,000 pcs.

1992 - For the manufacture of ELCBs, the Company signed another Technical

Collaboration with M/s Schiele Industrieworke, Germany.

1994 - The company successfully launched the latest IEC design contractors, relays, and

motor starters for the first time in India which have been well received in the market.

The company has finalized tie-ups in UAE, Oman, Kuwait and Egypt for marketing

its vast range of products in these countries.

1995 - The Company has introduced Product Managers and Industrial Teams to emphasize

the product mix and to strengthen its presence in all market segments.

1996 - Schiele industriwerke, Germany, who have been our collaborators for ELCBs, have

entered into a new technical collaboration with the company for quality up gradation

for its products in the control gear division.

The company decided to enter into the manufacture of Three Phase Energy Meters for

industrial applications.

Keeping in view business synergy's with the Cable Industry, the Company has entered

into the manufacture of low tension power cables.

Havell's group signed a Joint Venture Agreement with Hanson Electrical, a group

company of the UK Pound 11 Billion Anglo-American conglomerate, Hanson Plc.,

one of the top ten Companies of UK.

1997 - One of the biggest achievements during the year is that the JV partners have tested the

MCBs and have entered into an agreement with the Company to exclusively market

the MCBs in the worldwide markets.

Havell's Dorman Smith Pvt. Ltd., U.K. JV company, wherein Havell's India Ltd is a

25% shareholder, with Electrium Ltd. UK with the introduction of state-of-the-art

‘DORMAN SMITH’ brand Moulded Case Circuit Breakers in India.

Havell's group, has signed a new JV agreement with Ampy Automation Digilog Ltd.,

UK.

1998 - Cable division at Alwar is now ISO-9001 certified.

Havell's group has signed a new JV agreement with the Deutsche Zahiergesellschaft

(DZG), Germany.

The 50:50 JV company Havell's Dorman Smith Ltd. in which Havell's India Ltd. is a

25% shareholder had launched Moulded Case Circuit Breakers last year in the Indian

market.

The Company also launched Crabtree brand modular plate switches which is being

perceived as the best available product in the market.

1999 - Electrical switchgear makers Havell's India has entered into a strategic partnership

with Cambridge Technology Partners

India for implementing ERP on a fast-track.

The company has a 50:50 joint venture with DZG of Germany for manufacture of

high-end electromechanical and electronic energy meters.

2000 - Havell's entered into a technical collaboration with Geyer in 1998 to manufacture

miniature circuit-breakers.

For MCBs, the company has a technical collaboration with Geyer AG of Germany,

with Schiele Industriewerke of Germany for RCCBs and with Peterriens Schaltechik

Gmbh for changeover switches.

The Company has entered into a joint venture agreement with Standard Electricals

Ltd., an unlisted company wherein the company hold 60% shareholding.

Havell's India Ltd has acquired a 60 per cent stake in Hyderabad-based Duke Arnics

Electronics Ltd.

2001 - The Company has been awarded the highest revenue payer award for the year 2000 in

the organised sector category. Havell`s India Ltd has informed BSE that the company

had earlier acquired 60% shareholding of Standard Electricals Ltd., Jalandhar, an

unlisted company.

The company has acquired the entire 100% shareholding of Standard Electricals

Ltd.,

by purchasing balance 40% shareholding of the company. The Standard Electricals

Ltd., has thus become a 100% subsidiary of company w.e.f. December 31,2001.

2004 - Forays into the luxury bathroom fittings and accessories segment under the Crabtree

Frattini brand name

Havells India Limited has sold out its entire shareholding of Standard Electricals

Limited, an un-listed public limited company which was a 100% subsidiary of the

Company. Consequently, with effect from such transfer, Standard Electricals Limited

is no longer a subsidiary of the Company.

2006 - Havells India Ltd has informed that Ms Sabina Geyer has resigned from the

Directorship of the Company with immediate effect.

2007 - Havells India Limited has appointed Mr.N Balasubramanian as additional director of

the Company who shall hold office up to the date of next Annual General Meeting.

Havell's India is under the QRG group and was set up in 1958, with its corporate office in

Noida. Havell's India is a company worth US$ 1 billion and is one of the leading companies

in India's equipment-power distribution industry. Havell's India Ltd. produces and supplies

low-voltage electrical equipments in India.

Havell's India Company has 3 divisions – consumer electrical durables, wires and cables, and

switchgears. It has entered into alliances with electrical companies like DZG, Electrium, and

Geyer AG and this has helped the company improve their technical expertise in the segment

of electrical products. A lot many international certifications such as KEMA, ASTA,

SEMKO, and CSA have been acquired by Havell's India.

All the manufacturing plants of Havell's India are highly technologically developed and as a

result, all the products are of the best quality. The turnover of the Havell's India Ltd.

amounted to Rs. 29308.25 lakh in 2003, Rs. 41922.40 lakh in 2004, and Rs. 66538.46 lakh in

2005.

The various products manufactured by the Havell's India are:

Cables

Fans

Switches

Capacitor

Bath accessories and fittings

Lightning solutions

Havell's India Ltd. had established its cables plant in Alwar in 1996. It is a unit which has

been certified with ISO: 9001-2000 for its standards in manufacturing cables and wires from

the best quality of raw materials. Its latest automatic laser controlled machines are also of

international standards. This has ensured that the wires and cables manufactured by Havell's

India are of the best quality. The company entered the fan business in 2003 and offers great

variety in order to satisfy client requirements.

Havell's India Company designs and produces capacitors by using S3 technology. The bath

accessories and fittings manufactured by the company are of the best quality and are available

in a wide variety. Havell's India has become the top-most company in India on the basis of its

quality of products which are of the world class standards and its pricing which is accessible

by the common man.

Havell’s exports its products to approximately 55 countries across the globe and has

marketing offices in the EU, the Middle East and the USA.The company is listed on the

Bombay Stock Exchange and the National Stock Exchange. Its consolidated revenues

amounted to EUR 207 million in 2005.Europe is critical to the company’s business,

contributing approximately 40 per cent to its total revenues, generated by exports in 2005.

FUTURE PLANS

As a part of its growth strategy, Havell’s is taking initiatives to tap potential markets in the

EU.The company has developed a strong brand presence through alliances with and the

acquisition of leading electrical equipment manufacturers in the region. It has also initiated

various segment-wise growth plans to drive growth in its overall operations. The company

has identified the housing and power sectors as future growth drivers and plans to tap these

spheres. Havell’s has plans to diversify its product portfolio by venturing into the electrical

motors and power capacitors space. It also aims to leverage its established brand presence in

these segments. The company expects to increase its exports by approximately 100 per cent

from 2005-07. Havell’s also plans to increase its capacity to ward off cost pressures and

reduce development costs.The company has plans to increase its brand presence and reach in

the EU through strong acquisitions. It has plans to expand its operations in the EU in-

organically and enhance its international presence.

FACTORS FOR SUCCESS

STRATEGIC ALLIANCES

The company has formed strategic alliances and partnerships with many leading players

operating in the end-to-end solutions in the power distribution equipment industry. Havell’s

has entered manufacturing alliances with several leading electrical companies such as

Electrium, Geyer AG, DZG, etc., which has assisted the company to leverage the technical

expertise and developing quality products in the electrical products segment. Havell’s has

efficiently leveraged alliances to gain an entry into global markets, developing a strong

product portfolio to capture them.The company has developed efficient partnerships to

increase its market penetration in the EU.

LEADING THE WAY THROUGH INNOVATION

Havell’s has focussed on research and development to produce novel products, at the same

time, reducing cost and upgrading the quality of its products.The company has a skilled

workforce that works on its R&D projects. It has also entered into alliances with several

companies, thereby facilitating sharing of technology. It has developed a good brand name by

introducing innovative products in the market, which has enabled it to penetrate the market

ELECTRIC MOTOR

An electric motor is a device using electrical energy to produce mechanical energy, nearly

always by the interaction of magnetic fields and current-carrying conductors. Traction motors

used on vehicles often perform both tasks.

Electric motors are found in myriad uses such as industrial fans, blowers and pumps, machine

tools, household appliances, power tools, and computer disk drives, among many other

applications. The smallest motors may be found in electric wristwatches. Electric motors may

be classified by the source of electric power, by their internal construction, and by

application.

The physical principle of production of mechanical force by the interaction of an electric

current and a magnetic field was known as early as 1821. Electric motors of increasing

efficiency were constructed throughout the 19th century, but commercial exploitation of

electric motors on a large scale required efficient electrical generators and electrical

distribution networks.

Principle

The principle of conversion of electrical energy into mechanical energy by electromagnetic

means was demonstrated by the British scientist Michael Faraday in 1821 and consisted of a

free-hanging wire dipping into a pool of mercury. A permanent magnet was placed in the

middle of the pool of mercury. When a current was passed through the wire, the wire rotated

around the magnet, showing that the current gave rise to a circular magnetic field around the

wire.

Categorization Of Electric Motors

The classic division of electric motors is:-

1). Alternating Current (AC) types,

2). Direct Current (DC) types.

3). Universal Motor ( DC motors that runs on AC power).

1. AC Motors

In 1882, Nikola Tesla invented the rotating magnetic field, and pioneered the use of a rotary

field of force to operate machines. He exploited the principle to design a unique two-phase

induction motor in 1883. In 1885, Galileo Ferraris independently researched the concept. In

1888, Ferraris published his research in a paper to the Royal Academy of Sciences in Turin.

Tesla had suggested that the commutators from a machine could be removed and the device

could operate on a rotary field of force. Professor Poeschel, his teacher, stated that would be

akin to building a perpetual motion machine. Tesla would later attain U.S. Patent 0,416,194,

Electric Motor (December 1889), which resembles the motor seen in many of Tesla's photos.

This classic alternating current electro-magnetic motor was an induction motor.

Michail Osipovich Dolivo-Dobrovolsky later invented a three-phase "cage-rotor" in 1890.

This type of motor is now used for the vast majority of commercial applications.

A typical AC motor consists of two parts:

An outside stationary stator having coils supplied with AC current to produce a rotating

magnetic field, and;

An inside rotor attached to the output shaft that is given a torque by the rotating field.

2. DC Motors

A DC motor is designed to run on DC electric power. Two examples of pure DC designs are

Michael Faraday's homopolar motor (which is uncommon), and the ball bearing motor, which

is (so far) a novelty. By far the most common DC motor types are the brushed and brushless

types, which use internal and external commutation respectively to create an oscillating AC

current from the DC source—so they are not purely DC machines in a strict sense.There are

four types of DC motor:

DC series motor

DC shunt motor

Permanent Magnet DC Motor

DC compound motor

DC compound motor - there are also two types:

o Cumulative compound

o Differentially compounded

3. Universal Motors

A variant of the wound field DC motor is the universal motor. The name derives from the fact

that it may use AC or DC supply current, although in practice they are nearly always used

with AC supplies. The principle is that in a wound field DC motor the current in both the

field and the armature (and hence the resultant magnetic fields) will alternate (reverse

polarity) at the same time, and hence the mechanical force generated is always in the same

direction. In practice, the motor must be specially designed to cope with the AC (impedance

must be taken into account, as must the pulsating force), and the resultant motor is generally

less efficient than an equivalent pure DC motor.

The advantage of the universal motor is that AC supplies may be used on motors which have

the typical characteristics of DC motors, specifically high starting torque and very compact

design if high running speeds are used. The negative aspect is the maintenance and short life

problems caused by the commutator. As a result such motors are usually used in AC devices

such as food mixers and power tools which are used only intermittently. Continuous speed

control of a universal motor running on AC is easily obtained by use of a thyristor circuit,

while stepped speed control can be accomplished using multiple taps on the field coil.

Household blenders that advertise many speeds frequently combine a field coil with several

taps and a diode that can be inserted in series with the motor (causing the motor to run on

half-wave rectified AC).

Uses

Electric motors are used in many, if not most, modern machines. Obvious uses would be in

rotating machines such as fans, turbines, drills, the wheels on electric cars, and conveyor

belts. Also, in many vibrating or oscillsting machines, an electric motor spins an irregular

figure with more area on one side of the axle than the other, causing it to appear to be moving

up and down.

Electric motors are also popular in robotics. They are used to turn the wheels of vehicular

robots, and servo motors are used to turn arms and legs in humanoid robots. In flying robots,

along with helicopters, a motor causes a propellor or wide, flat blades to spin and create drag

force, allowing vertical motion.

In industrial and manufacturing businesses, electric motors are used to turn saws and blades

in cutting and slicing processes, and to spin gears and mixers (the latter very common in food

manufacturing). Linear motors are often used to push products into containers horizontally.

Many kitchen appliances also use electric motors to accomlish various jobs. Food processors

and grinders spin blades to chop and break up foods. Blenders use electric motors to mix

liquids, and microwave ovens use motors to turn the tray food sits on. Toaster ovens also use

electric motors to turn a conveyor in order to move food over heating elements.

ELECTRICAL GENERATOR

In electricity generation, an electrical generator is a device that converts mechanical energy to

electrical energy, generally using electromagnetic induction. The reverse conversion of

electrical energy into mechanical energy is done by a motor; motors and generators have

many similarities. A generator forces electric charges to move through an external electrical

circuit, but it does not create electricity or charge, which is already present in the wire of its

windings. It is somewhat analogous to a water pump, which creates a flow of water but does

not create the water inside. The source of mechanical energy may be a reciprocating or

turbine steam engine, water falling through a turbine or waterwheel, an internal combustion

engine, a wind turbine, a hand crank, compressed air or any other source of mechanical

energy.

Historic Developments

Before the connection between magnetism and electricity was discovered, electrostatic

generators were invented that used electrostatic principles. These generated very high

voltages and low currents. They operated by using moving electrically charged belts, plates

and disks to carry charge to a high potential electrode. The charge was generated using either

of two mechanisms:

Electrostatic induction

The turboelectric effect, where the contact between two insulators leaves them

charged.

Because of their inefficiency and the difficulty of insulating machines producing very high

voltages, electrostatic generators had low power ratings and were never used for generation

of commercially-significant quantities of electric power. The Wimshurst machine and Van de

Graaff generator are examples of these machines that have survived.

Jedlik's Dynamo

In 1827, Hungarian Anyos Jedlik started experimenting with electromagnetic rotating devices

which he called electromagnetic self-rotors. In the prototype of the single-pole electric starter

(finished between 1852 and 1854) both the stationary and the revolving parts were

electromagnetic. He formulated the concept of the dynamo at least 6 years before Siemens

and Wheatstone but didn't patent it as he thought he wasn't the first to realize this. In essence

the concept is that instead of permanent magnets, two electromagnets opposite to each other

induce the magnetic field around the rotor. Jedlik's invention was decades ahead of its time.

Faraday Disk

In 1831-1832 Michael Faraday discovered the operating principle of electromagnetic

generators. The principle, later called Faraday's law, is that a potential difference is generated

between the ends of an electrical conductor that moves perpendicular to a magnetic field. He

also built the first electromagnetic generator, called the 'Faraday disc', using a copper disc

rotating between the poles of a horseshoe magnet. It produced a small DC voltage, and large

amounts of current.

This design was inefficient due to self-cancelling counter flows of current in regions not

under the influence of the magnetic field. While current flow was induced directly underneath

the magnet, the current would circulate backwards in regions outside the influence of the

magnetic field. This counter flow limits the power output to the pickup wires, and induces

waste heating of the copper disc. Another disadvantage was that the output voltage was very

low, due to the single current path through the magnetic flux. Experimenters found that using

multiple turns of wire in a coil could produce higher more useful voltages. Since the output

voltage is proportional to the number of turns, generators could be easily designed to produce

any desired voltage by varying the number of turns. Wire windings became a basic feature of

all subsequent generator designs.

The first Turbo generator Designed by the Hungarian engineer Ottó Bláthy in 1903

The Dynamo was the first electrical generator capable of delivering power for industry. The

dynamo uses electromagnetic principles to convert mechanical rotation into a pulsing direct

electric current through the use of a commutator. The first dynamo was built by Hippolyte

Pixii in 1832.

Through a series of accidental discoveries, the dynamo became the source of many later

inventions, including the DC electric motor, the AC alternator, the AC synchronous motor,

and the rotary converter.

A dynamo machine consists of a stationary structure, which provides a constant magnetic

field, and a set of rotating windings which turn within that field. On small machines the

constant magnetic field may be provided by one or more permanent magnets; larger machines

have the constant magnetic field provided by one or more electromagnets, which are usually

called field coils.

Large power generation dynamos are now rarely seen due to the now nearly universal use of

alternating current for power distribution and solid state electronic AC to DC power

conversion. But before the principles of AC were discovered, very large direct-current

dynamos were the only means of power generation and distribution. Now power generation

dynamos are mostly a curiosity.

Terminology

The two main parts of a generator or motor can be described in either mechanical or electrical

terms.

Mechanical:

Rotor: The rotating part of an alternator, generator, dynamo or motor.

Stator: The stationary part of an alternator, generator, dynamo or motor.

Electrical:

Armature: The power-producing component of an alternator, generator, dynamo or

motor. In a generator, alternator, or dynamo the armature windings generate the

electrical current. The armature can be on either the rotor or the stator.

Field: The magnetic field component of an alternator, generator, dynamo or motor.

The magnetic field of the dynamo or alternator can be provided by either

electromagnets or permanent magnets mounted on either the rotor or the stator. (For a

more technical discussion, refer to the Field coil article.)

Because power transferred into the field circuit is much less than in the armature circuit, AC

generators nearly always have the field winding on the rotor and the stator as the armature

winding. Only a small amount of field current must be transferred to the moving rotor, using

slip rings. Direct current machines necessarily have the commutator on the rotating shaft, so

the armature winding is on the rotor of the machine.

TRANSFORMER

A variety of types of electrical transformer are made for different purposes. Despite their

design differences, the various types employ the same basic principle as discovered in 1831

by Michael Faraday, and share several key functional parts.

Power Transformers

This is the most common type of transformer, widely used in appliances to convert mains

voltage to low voltage to power electronics

Widely available in power ratings ranging from mW to MW

Insulated laminations minimize eddy current losses

Small appliance and electronic transformers may use a split bobbin, giving a high

level of insulation between the windings

Rectangular core

Core laminate stampings are usually in EI shape pairs. Other shape pairs are

sometimes used.

Mumetal shields can be fitted to reduce EMI (electromagnetic interference)

A screen winding is occasionally used between the 2 power windings

Small appliance and electronics transformers may have a thermal cut out built in

Occasionally seen in low profile format for use in restricted spaces

laminated core made with silicon steel with high permeability

Auto-Transformer

An autotransformer has only a single winding, which is tapped at some point along the

winding. AC or pulsed voltage is applied across a portion of the winding, and a higher (or

lower) voltage is produced across another portion of the same winding. The higher voltage

will be connected to the ends of the winding, and the lower voltage from one end to a tap. For

example, a transformer with a tap at the center of the winding can be used with 230 volts

across the entire winding, and 115 volts between one end and the tap. It can be connected to a

230-volt supply to drive 115-volt equipment, or reversed to drive 230-volt equipment from

115 volts. Since the current in the windings is lower, the transformer is smaller, lighter

cheaper and more efficient. For voltage ratios not exceeding about 3:1, an autotransformer is

cheaper, lighter, smaller and more efficient than an isolating (two-winding) transformer of the

same rating. Large three-phase autotransformers are used in electric power distribution

systems, for example, to interconnect 33 kV and 66 kV sub-transmission networks.

In practice, transformer losses mean that autotransformers are not perfectly reversible; one

designed for stepping down a voltage will deliver slightly less voltage than required if used to

step up. The difference is usually slight enough to allow reversal where the actual voltage

level is not critical. This is true of isolated winding transformers too.

Polyphase Transformers

For three-phase power, three separate single-phase transformers can be used, or all three

phases can be connected to a single polyphase transformer. The three primary windings are

connected together and the three secondary windings are connected together. The most

common connections are Y-Delta, Delta-Y, Delta-Delta and Y-Y. A vector group indicates

the configuration of the windings and the phase angle difference between them. If a winding

is connected to earth (grounded), the earth connection point is usually the center point of a Y

winding. If the secondary is a Delta winding, the ground may be connected to a center tap on

one winding (high leg delta) or one phase may be grounded (corner grounded delta). A

special purpose polyphase transformer is the zigzag transformer. There are many possible

configurations that may involve more or fewer than six windings and various tap connections.

Oil Cooled Transformer

For large transformers used in power distribution or electrical substations, the core and coils

of the transformer are immersed in oil which cools and insulates. Oil circulates through ducts

in the coil and around the coil and core assembly, moved by convection. The oil is cooled by

the outside of the tank in small ratings, and in larger ratings an air-cooled radiator is used.

Where a higher rating is required, or where the transformer is used in a building or

underground, oil pumps are used to circulate the oil and an oil-to-water heat exchanger may

also be used.[1] Formerly, indoor transformers required to be fire-resistant used PCB liquids;

since these are now banned, substitute fire-resistant liquids such as silicone oils are instead

used.

Pulse Transformers

A pulse transformer is a transformer that is optimised for transmitting rectangular electrical

pulses (that is, pulses with fast rise and fall times and a relatively constant amplitude). Small

versions called signal types are used in digital logic and telecommunications circuits, often

for matching logic drivers to transmission lines. Medium-sized power versions are used in

power-control circuits such as camera flash controllers. Larger power versions are used in the

electrical power distribution industry to interface low-voltage control circuitry to the high-

voltage gates of power semiconductors. Special high voltage pulse transformers are also used

to generate high power pulses for radar, particle accelerators, or other high energy pulsed

power applications.

To minimise distortion of the pulse shape, a pulse transformer needs to have low values of

leakage inductance and distributed capacitance, and a high open-circuit inductance. In power-

type pulse transformers, a low coupling capacitance (between the primary and secondary) is

important to protect the circuitry on the primary side from high-powered transients created by

the load. For the same reason, high insulation resistance and high breakdown voltage are

required. A good transient response is necessary to maintain the rectangular pulse shape at

the secondary, because a pulse with slow edges would create switching losses in the power

semiconductors.

The product of the peak pulse voltage and the duration of the pulse (or more accurately, the

voltage-time integral) is often used to characterise pulse transformers. Generally speaking,

the larger this product, the larger and more expensive the transformer.

Pulse transformers by definition have a duty cycle of less than 1, whatever energy stored in

the coil during the pulse must be "dumped" out before the pulse is fired again.

Audio Transformers

Transformers in a tube amplifier. Output transformers are on the left. The power supply

toroidal transformer is on right.

Audio transformers are usually the factor which limit sound quality when used; electronic

circuits with wide frequency response and low distortion are relatively simple to design.

Transformers are also used in DI boxes to convert high-impedance instrument signals (e.g.

bass guitar) to low impedance signals to enable them to be connected to a microphone input

on the mixing console.

A particularly critical component is the output transformer of an audio power amplifier.

Valve circuits for quality reproduction have long been produced with no other (inter-stage)

audio transformers, but an output transformer is needed to couple the relatively high

impedance (up to a few hundred ohms depending upon configuration) of the output valve(s)

to the low impedance of a loudspeaker. (The valves can deliver a low current at a high

voltage; the speakers require high current at low voltage.) Most solid-state power amplifiers

need no output transformer at all.

For good low-frequency response a relatively large iron core is required; high power handling

increases the required core size. Good high-frequency response requires carefully designed

and implemented windings without excessive leakage inductance or stray capacitance. All

this makes for an expensive component.

Early transistor audio power amplifiers often had output transformers, but they were

eliminated as designers discovered how to design amplifiers without them.

SINGLE LINE DIAGRAM

HT SIDE

33 KV Supply (R.S.E.B.)

Drop Out Fuse (33KV)

Lightning Arrester (33KV)

Gang Operated Switch (G.O) With Earthing

M.O.C.B or V.C.B (33KV)

Current Transformer (5 A )

Potential Transformer (33KV / 110 V)

Three Phase Step Down Transformer (Delta - Star)2000 KVA,

L.V. Side - At No Load (433 V / 2666.7 A)

The first device encountered in a substation is typically a disconnect switch.

The most commonly used switch in small to medium substations is a GANG-OPERATED

SWITCH. "Gang-operated" because the three separate switches for each phase are operated

as a group from a single control.

The purpose of this switch is to disconnect the substation from the incoming line, not to

disconnect the transformer from the load. It is like a large safety switch with no load breaking

capability. It can only break, or "interrupt" the relatively small "magnetizing current" of the

substation transformer. (This is the small amount of current needed to set up the magnetic

field in the transformer core.) A substation must first be disconnected from its secondary or

load side before the primary or high voltage side can be disconnected using the disconnect

switch.

The next device encountered in a substation is the HIGH VOLTAGE POWER FUSES /

DROP OUT FUSE. Depending on the line voltage, they may be up to six feet long. These

fuses stop the flow of current in the event of an internal fault or short-circuit in the

transformer. Overloads due to faults or short circuits on the distribution side of the substation

are prevented by low voltage protective equipment. Drop out fuse are complete with fuse

carrier of fiber glass tube with both end heavily tinned non ferrous metal parts. The brush

type phosphor bronze contacts provide positive high pressure multilane connection and

wiping and cleaning action on closing. The pressure exerted by the contacts initiates the

opening movement of the fuse carrier copper & copper alloys high pressure heavily tinned

metal contacts for fix top contacts assembly and bottom contact assembly. The D.O. Fuse

units are manufactured up to and including 33kv system.

The next device encountered in a substation is LIGHTNING ARRESTER A lightning

arrester is a device used on electrical power systems to protect the insulation on the system

from the damaging effect of lightning. Metal oxide varistors (movs) have been used for

power system protection since the mid 1970s. The typical lightning arrester also known as

surge arrester has a high voltage terminal and a ground terminal. When a lightning surge or

switching surge travels down the power system to the arrester, the current from the surge is

diverted around the protected insulation in most cases to earth.

The next device encountered in a substation is TRANSMISSION LEVEL CIRCUIT

BREAKERS OR CIRCUIT SWITCHERS / MINIMUM OIL CIRCUIT BREAKER are

some of the last devices found in a substation. They are utilized when there is a need to

remotely switch the incoming or outgoing transmission circuits in a substation. They also

may be used in place of high voltage power fuses.

The Circuit Breakers are automatic Switches which can interrupt fault currents. The part of

the Circuit Breakers connected in one phase is called the pole. A Circuit Breaker suitable for

three phase system is called a ‘triple-pole Circuit Breaker. Each pole of the Circuit Breaker

comprises one or more interrupter or arc-extinguishing chambers. The interrupters are

mounted on support insulators. The interrupter encloses a set of fixed and moving contact's

The moving contacts can be drawn apart by means of the operating links of the operating

mechanism. The operating mechanism of the Circuit Breaker gives the necessary energy for

opening and closing of contacts of the Circuit Breakers.

The arc produced by the separation of current carrying contacts is interrupted by a suitable

medium and by adopting suitable techniques for arc extinction. The Circuit Breaker can be

classified on the basis of the arc extinction medium.

The Fault Clearing Process

During the normal operating condition the Circuit Breaker can be opened or closed by a

station operator for the purpose of Switching and maintenance. During the abnormal or faulty

conditions the relays sense the fault and close the trip circuit of the Circuit Breaker.

Thereafter the Circuit Breaker opens. The Circuit Breaker has two working positions, open

and closed. These correspond to open Circuit Breaker contacts and closed Circuit Breaker

contacts respectively. The operation of automatic opening and closing the contacts is

achieved by means of the operating mechanism of the Circuit Breaker. As the relay contacts

close, the trip circuit is closed and the operating mechanism of the Circuit Breaker starts the

opening operation. The contacts of the Circuit Breaker open and an arc is draw between

them. The arc is extinguished at some natural current zero of A.C. wave. The process of

current interruption is completed when the arc is extinguished and the current reaches final

zero value. The fault is said to be cleared. The process of fault clearing has the following

sequence:

1- Fault Occurs. As the fault occurs, the fault impedance being low, the currents increase and

the relay gets actuated. The moving part of the relay move because of the increase in the

operating torque. The relay takes some time to close its contacts.

2 - Relay contacts close the trip circuit of the Circuit Breaker closes and trip coil is energized.

3 - The operating mechanism starts operating for the opening operation.

     The Circuit Breaker contacts separate.

4 - Arc is drawn between the breaker contacts. The arc is extinguished

      in the Circuit Breaker by suitable techniques. The current reaches final zero

      as the arc is extinguished and does not restrict again.

The type of the Circuit Breaker is usually identified according to the medium of arc

extinction. The classification of the Circuit Breakers based on the medium of arc extinction is

as follows:

(1) Air break' Circuit Breaker. (Miniature Circuit Breaker).

(2) Oil Circuit Breaker (tank type of bulk oil)

(3) Minimum oil Circuit Breaker.

(4) Air blast Circuit Breaker.

(5) Vacuum Circuit Breaker.

(6) Sulphur hexafluoride Circuit Breaker. (Single pressure or Double Pressure).

Type Medium Voltage, Breaking Capacity

1 – Air break Circuit

Breaker

Air at atmospheric

pressure

(430 – 600) V– (5-15)MVA

(3.6-12) KV -  500 MVA

2 – Miniature CB. Air at atmospheric

pressure

(430-600 ) V

3 – Tank Type oil CB. Dielectric oil (3.6 – 12) KV

4 – Minimum Oil CB. Dielectric oil (3.6 - 145 )KV

5 – Air Blast CB. Compressed Air

(20 – 40 ) bar

245 KV, 35000 MVA

up to 1100 KV, 50000 MVA

6 – SF6 CB. SF6 Gas 12 KV, 1000 MVA

36 KV , 2000 MVA

145 KV, 7500 MVA

245 KV , 10000 MVA

7 – Vacuum  CB. Vacuum 36 KV, 750 MVA

8 – H.V.DC CB. Vacuum , SF6 Gas 500 KV DC

The next device encountered in a substation is INSTRUMENT TRANSFORMERS

i.e. Current Transformer & Potential Transformer

In electrical engineering, a current transformer (CT) is used for measurement of electric

currents. Current transformers are also known as instrument transformers. When current in a

circuit is too high to directly apply to measuring instruments, a current transformer produces

a reduced current accurately proportional to the current in the circuit, which can be

conveniently connected to measuring and recording instruments. A current transformer also

isolates the measuring instruments from what may be very high voltage in the primary circuit.

Current transformers are commonly used in metering and protective relays in the electrical

power industry.

Design

Like any other transformer, a current transformer has a primary winding, a magnetic core,

and a secondary winding. The alternating current flowing in the primary produces a magnetic

field in the core, which then induces current flow in the secondary winding circuit. A primary

objective of current transformer design is to ensure that the primary and secondary circuits

are efficiently coupled, so that the secondary current bears an accurate relationship to the

primary current.

The most common design of CT consists of a length of wire wrapped many times around a

silicon steel ring passed over the circuit being measured. The CT's primary circuit therefore

consists of a single 'turn' of conductor, with a secondary of many hundreds of turns. The

primary winding may be a permanent part of the current transformer, with a heavy copper bar

to carry current through the magnetic core. Window-type current transformers are also

common, which can have circuit cables run through the middle of an opening in the core to

provide a single-turn primary winding. When conductors passing through a CT are not

centered in the circular (or oval) opening, slight inaccuracies may occur.

Current transformers used in metering equipment for three-phase 400 ampere electricity

supply

Usage

Current transformers are used extensively for measuring current and monitoring the operation

of the power grid. Along with voltage leads, revenue-grade CTs drive the electrical utility's

watt-hour meter on virtually every building with three-phase service, and every residence

with greater than 200 amp service.

The CT is typically described by its current ratio from primary to secondary. Often, multiple

CTs are installed as a "stack" for various uses (for example, protection devices and revenue

metering may use separate CTs). Similarly potential transformers are used for measuring

voltage and monitoring the operation of the power grid.

Safety Precautions

Care must be taken that the secondary of a current transformer is not disconnected from its

load while current is flowing in the primary, as the transformer secondary will attempt to

continue driving current across the effectively infinite impedance. This will produce a high

voltage across the open secondary (into the range of several kilovolts in some cases), which

may cause arcing. The high voltage produced will compromise operator and equipment safety

and permanently affect the accuracy of the transformer.

Accuracy

The accuracy of a CT is directly related to a number of factors including:

Burden

Burden class/saturation class

Rating factor

Load

External electromagnetic fields

Temperature and

Physical configuration.

The selected tap, for multi-ratio CT's

Voltage Transformers

Voltage transformers (VTs) or potential transformers (PTs) are another type of instrument

transformer, used for metering and protection in high-voltage circuits. They are designed to

present negligible load to the supply being measured and to have a precise voltage ratio to

accurately step down high voltages so that metering and protective relay equipment can be

operated at a lower potential. Typically the secondary of a voltage transformer is rated for 69

or 120 Volts at rated primary voltage, to match the input ratings of protection relays.

The transformer winding high-voltage connection points are typically labelled as H1, H2

(sometimes H0 if it is internally grounded) and X1, X2, and sometimes an X3 tap may be

present. Sometimes a second isolated winding (Y1, Y2, Y3) may also be available on the

same voltage transformer. The high side (primary) may be connected phase to ground or

phase to phase. The low side (secondary) is usually phase to ground.

The terminal identifications (H1, X1, Y1, etc.) are often referred to as polarity. This applies

to current transformers as well. At any instant terminals with the same suffix numeral have

the same polarity and phase. Correct identification of terminals and wiring is essential for

proper operation of metering and protection relays.

While VTs were formerly used for all voltages greater than 240V primary, modern meters

eliminate the need VTs for most secondary service voltages. VTs are typically used in

circuits where the system voltage level is above 600 V. Modern meters eliminate the need of

VT's since the voltage remains constant and it is measured in the incoming supply.

Potential Transformer is designed for monitoring single phase and three phase power line

voltages in power metering applications

The primary terminal can be connected either in line to line or in line to neutral configuration.

Fused Transformer models are designated by a suffix of “F” for one fuse or “FF” for two

fuses.

A Potential Transformer is a special type of transformer that allows meters to take readings

from electrical service connections with higher voltage (potential) than the meter is normally

capable of handling without at Potential Transformer.

Three-Phase Transformer Circuits

Since Three-Phase is used so often for power distribution systems, it makes sense that we

would need Three-Phase transformers to be able to step voltages up or down. This is only

partially true, as regular single-phase transformers can be ganged together to transform power

between two three-Phase systems in a variety of configurations, eliminating the requirement

for a special Three-Phase transformer. However, special Three-Phase transformers are built

for those tasks, and are able to perform with less material requirement, less size, and less

weight than their modular counterparts.

A Three-Phase Transformer is made of three sets of primary and secondary windings, each

set wound around one leg of an iron core assembly. Essentially it looks like three single

Phase transformers sharing a joined core as in Figure below.

Three-Phase Transformer core has three set of windings..

Those sets of primary and secondary windings will be connected in either Δ or Y

configurations to form a complete unit. The various combinations of ways that these

windings can be connected together in will be the focus of this section.

Whether the winding sets share a common core assembly or each winding pair is a separate

Transformer, the winding connection options are the same:

Primary - Secondary

    Y       -           Y

    Y       -           Δ

    Δ       -           Y

    Δ       -           Δ

The reasons for choosing a Y or Δ configuration for Transformer winding connections are the

same as for any other Three-Phase application: Y connections provide the opportunity for

multiple voltages, while Δ connections enjoy a higher level of reliability (if one winding fails

open, the other two can still maintain full line voltages to the load).

Probably the most important aspect of connecting three sets of primary and secondary

windings together to form a Three-Phase Transformer bank is paying attention to proper

winding phasing (the dots used to denote “polarity” of windings). Remember the proper

phase relationships between the phase windings of Δ and Y: (Figure below)

(Y) The center point of the “Y” must tie either all the “-” or all the “+” winding points

together. (Δ) The winding polarities must stack together in a complementary manner ( + to

-).

Getting this phasing correct when the windings aren't shown in regular Y or Δ configuration

can be tricky. Let me illustrate, starting with Figure below.

Inputs A1, A2, A3 may be wired either “Δ” or “Y”, as may outputs B1, B2, B3.

Three individual transformers are to be connected together to transform power from one

Three Phase system to another. First, I'll show the wiring connections for a Δ -Y

configuration: Figure below.

Phase wiring for “Δ-Y”Transformer.

Such a configuration (Figure above) would allow for the provision of multiple voltages (line-

to-line or line-to-neutral) in the second power system, from a source power system having no

neutral.