Introduction Power System

8/10/2019 Introduction Power System

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1 Importance of Electrical Energy

2 Generation of Electrical Energy

3 Sources of Energy

4 Comparison of Energy Sources

CONTENTS

6 Relationship Among Energy Units

7 Efficiency

8 Calorific Value of Fuels

9 Advantages of Liquid Fuels Over Solid Fuels

10 Advantages of Solid Fuels Over Liquid Fuels


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Importance & Benefits of Electrical Energy

1.Convenient form

2.Easy control

3.Greater flexibility

4.Cheapness

5.Cleanliness

6.High transmission efficiency.

7. Renewable source of energy

8. Symbol of Development

9. Back bone of economy


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Electrical Power SystemElectrical Power System

Electrical Power System consists of three main

components

Generation

Transm ss on

Distribution

Generation Transmission Distribution


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Basic Conventional Power SystemLayout

Conventional (non-renewable)

primary energy source

i i l


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Basic Conventional Power System Layout


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The Organisation for Economic Co-operation and

Development Survey for World Electricity

Consumptions by Regions


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World Electricity Production Sources

f l l


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Generation of Electrical Energy

The conversion of energy available in different forms in nature into

electrical energy is known as generation of electrical energy.

Energy is available in various forms from different natural sources

such as:

1.Pressure head of water2.Chemical energy of fuels

3.Nuclear energy of radioactive substances

4. Wind

5. Solar6. Piezo electric


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S f E


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Sources of Energy

The heat energy radiated focused by means of reflectors

known as concentrated solar power.Heat can be used to raise steam for electrical energy.

PV cells can generate voltage from sunlight

Limitation: 1. Requires large area

2. Cannot be used in cloudy days or at night

3.Uneconomical method

For continuous electrical supply, the generator is

arranged to charge the batteries. These batteriessupply the energy when the wind stops.

Advantages: Minimum operational costMaintenance and generation costs are negligible


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Drawbacks: 1.Variable output

2.Unreliable because of uncertainty about wind pressure

3.Power generated is quite small.

water is stored and potential energy of head

converted into mechanical energy that drives the

turbine and alternator.

This method is very popular because it has low production and

maintenance costs.

Solid fuel as coal

Liquid fuel as oil

Gas fuel as natural gas


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The heat energy of these fuels is converted into mechanical

energy by suitable prime movers such as:

Steam engines

Steam turbines

Internal combustion engines

ue s reserves are m n s ng ay y ay

Fission of uranium and other fissionable materials

1 kg of nuclear fuel is equal to that produced by 4500 tonnes of

coal

Nuclear fission heat raises the steam to drive steam turbine for

electrical energy.


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There are some difficulties in the use of nuclear energy:

1. High cost of nuclear Plant

2. Problem of disposal of radioactive waste

3. Dearth of trained personnel to handle the plant

Energy Utilization

Comparison of Energy Sources


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Comparison of Energy Sources


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Comparative Prices of Different Generation


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Comparative Prices of Different Generation

Sources

Units of Energy


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Units of Energy

Relationship Among Energy Units


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Relationship Among nergy Units

1.Electrical and Mechanical

1 kWh = 36 105 Joules

2.Heat and Mechanical

1 calorie = 418 Joules

3. Electrical and Heat

1 kWh = 860 103 calories or 860 kcal

Efficiency


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y

The output energy divided by the input energy is called

energy efficiency or simply efficiency of the system.

As power is the rate of energy flow, therefore

1.1 Mechanical energy is supplied to a d.c. generator at the rate of 4200 J/s. The

generator delivers 322 A at 120 V.

(i) What is the percentage efficiency of the generator ?

(ii) How much energy is lost per minute of operation ?

Calorific Value of Fuels


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The amount of heat produced by the complete combustion of a unit

weight of fuel is known as its calorific value.

Advantages of Liquid Fuels Over Solid Fuels


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1. Handling of liquid fuels is easier ,require less storage space.

2. The combustion of liquid fuels is uniform.

3. The solid fuels burn with great difficulty. liquid fuels burn with

a fair degree of ease and attain high temperature very quickly

compare o so ue s.

4.The waste product of solid fuels is a large, liquid fuels leave

no or very little ash after burning.

5. The firing of liquid fuels can be easily controlled. This permits

to meet the variation in load demand easily.

Advantages of Solid Fuels Over Liquid Fuels


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1. In case of liquid fuels, there is a danger of explosion

2. Liquids fuels are costlier as compared to solid fuels.

3. Sometimes liquid fuels give unpleasant odours during burning.

4.Liquid fuels require special types of burners for burning.

5. Liquid fuels pose problems in cold climates since the oil

stored in the tanks is to be heated in order to avoid the stoppage

of oil flow.


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Distributed Generation

Distributed generation, also called on-sitegeneration, dispersed generation, embeddedgeneration, decentralized generation, decentralizedenergy, distributed energy or district energy,

enerates electricit from man small ener sources.

Distributed generation allows collection of energy frommany sources and may give lower environmental

impacts and improved security of supply.


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Thank You

Introduction Power System

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