Final Year Project WSE

MOBILE CHARGING WITH

APPLICATION OF HYBRID SOLAR

ENERGY

PRESENTED BY

SHUBHRANSHU 091091101143

SUMIT KR. SHEKHAR 091091101152

RAJIV KR. RANJAN 91091101105

Dr.MGR

Educational and Research Institute

University

A PROJECT REPORT SUBMITTED TO

Faculty of Engineering and Technology

In partial fulfillment of the requirements for the award of the degree

BACHELOR OF TECHNOLOGY IN

Department of Electrical and Electronics Engineering

April 2013

EEE – Project Report 2013 – Dr.M.G.R University

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Dr.MGR

Educational and Research Institute

University

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

CERTIFICATE

This is to certify that this is a bonafide project work done by Mr.

Shubhranshu, Mr. Sumit Kr. Shekhar & Mr. Rajiv Kr. Ranjan Reg. No.:

091091101143, 091091101152 & 091091101105 respectively of IV year

B.Tech.(Electrical & Electronics Engineering) branch for the project title on

―Mobile Charging with Application Of Hybrid Solar Energy‖ during the

academic year 2012-2013.

Signature of the Internal Guide Signature of the Head of the department

Submitted for the project Viva-voce on _____________

Internal Examiner External Examiner


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ABSTRACT

The main function of Hybrid solar energy is that it obtains energy from both sources-

solar energy with the help of PV panels & wind energy from wind turbines. Solar

panel absorbs the sunrays and converts it into DC current. In addition, a wind turbine

move due to the force of wind & its rotor connects with a generator rotates and gives

DC current. Now both the current works simultaneously and goes to the circuit board

and charge the mobile phones connected with the help of wires. A digital clock with

temperature reader is also connected to this system.

This paper proposes a hybrid energy system, which combines photovoltaic (PV) and

wind power as an alternative source small-scale electric power, where the

conventional production is not practical. The proposed system is attractive because of

its simplicity, ease of control and low costs. Complete descriptions of the proposed

hybrid system with the results of detailed simulations, which determine feasibility, are

given to demonstrate the availability of the proposed system in this paper.

TABLE OF CONTENTS

ABSTRACT ...................................................................................................................................... i

TABLE OF CONTENTS ................................................................................................................. ii

LIST OF FIGURES ....................................................................................................................... iiii

ACKNOWLEDGEMENT……………………………………………………………………...

Chapter 1 Introduction ..................................................................................................................... 2

1.1 Problem .................................................................................................................................. 4

1.3 Scope and Objectives ............................................................................................................. 5

Chapter 2 Literature Review ............................................................................................................ 7

2.1 Solar Energy System ............................................................................................................. 8

2.2 Wind Energy System .......................................................................................................... 10

2.3 Hybrid Energy System……………………………………………………………………13

Chapter 3 Methodology and Implementation ................................................................................ 16

3.1 Methodology ....................................................................................................................... 16

3.2 Implementation ................................................................................................................... 17

Chapter 4 Results ........................................................................................................................... 22

Chapter 5 Conclusions and Future Work ....................................................................................... 25

5.1 Conclusions ........................................................................................................................ 25

5.2 Future Work ........................................................................................................................ 26

REFERENCES .............................................................................................................................. 27


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LIST OF FIGURES

Fig. 1. Solar Insolation In india………………………………………………………9

Fig. 2. Annual Mean Daily Global Solar Electric Conversion Potential In

India(MW)……………………………………………………………………………10

Fig. 3. WIND MAP OF INDIA……………………………………………………12

Fig. 4. BLOCK DIAGRAM: WIND/SOLAR HYBRID POWER SYSTEM………14

ACKNOWLEDGEMENT

We would first like to thank our beloved founder-chancellor

Thiru A.C. Shanmugam and beloved president Er.A.C.S Arun

Kumar for all the encouragement and support extended to us

during the tenure of this project and also our years of studies in

this university.

We express our heartfelt thanks to our Head of the

Department, Prof.L.Ramesh, who has been actively involved and

very influential from the start till the completion of our project.

We thank our project coordinator Dean Dr. Sathya

Moorthy for her espousal and for having instilled in us the

confidence to complete our project on time.

We also thank our guide Mr. S. Balamurugan for his

guidance, assistance and cooperation that facilitated the

successful conclusion of our project.

We would also like to thank all teaching and non-teaching

staff of the Electrical & Electronics Engineering Department for

their constant support and encouragement given to us.

We are also thankful to our parents & all our friends who

have extended their help in various ways during the course of this

project.


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CHAPTER 1


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INTRODUCTION

Energy has been playing an important role in human and economic development and

world peace. Since the world economic resuscitation and boom. World total energy

annual consumption is increased. While fossil fuel (i.e. coal ,oil, natural gas) provided

three quarters of the total. At current energy consumption rate proven coal reserve

should last for about 200 years . Oil for approximately 40 years and natural gas for

annual 60 years with the contradiction between rapid development.

The main function of Hybrid solar energy is that it obtain energy from both sources-

solar energy with the help of PV panels & wind energy from wind turbines. Solar

panel absorbs the sunrays and convert it into DC current. And wind turbine moves

due to the force of wind & its rotor connects with a generator also rotates and gives

AC current. This AC current converts into DC with the help of AC-DC converter.

Now both the current works simultaneously and goes to the circuit board and charge

the mobile phones connected with the help of wires.

Renewable energy from wind and solar photovoltaic are the most ecological type of

energy to use. They are based on a clean and efficient modern technology, which

offers a glimmer of hope for a future based on sustainable and pollution-free

technology. The importance of using renewable energy system, including solar

photovoltaic (PV) and wind has been attracted much these days, because the

electricity demand is growing rapidly all over the world. Therefore, there is an urgent

need for renewable energy resources, and formulated as a national strategy for the

development of renewable energy applications. For this purpose, uninterrupted efforts

to develop systems more attracting with low costs, a high efficiency and multifunction

are required. Small-scale stand-alone power generation systems are an important

alternative source of electrical energy, finding applications in the places where the

conventional production is not practical. Consider, for example, remote villages in

developing countries or ranches located far away from main power lines. The

certainty of load demands at any time is considerably increased by the hybrid

production systems, which use more than one source of energy. It is possible the high

outputs production factors combine wind turbines and photovoltaic arrays with

storage technology to master the movements of the production facility. An effective


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energy storage is necessary to obtain a constant power, the power delivered by wind

and solar should be easily converted into energy stored.

IMPORTANCE OF RENEWABLE ENERGY

The global search and the rise in the cost of conventional fossil fuel is making supply-

demand o f electricity product almost impossible especially in some remote areas.

Generator which are often used as an alternative to conventional power supply

systems are known to be run only during hours of the day, and the e cost of fueling

them is increasingly becoming difficult if they are to be used for commercial

purposes. There is a growing awareness that renewable energy such as

photovoltaic system and Wind power have an important role to play in order to

save the situation. Figure 1 is the schematic layout of Solar-Wind Hybrid system that

can supply either dc or ac energy or both.


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DEFINITION OF HYBRID POWER SYSTEMS

Hybrid power systems (HPS) are any autonomous electricity generating systems,

incorporating more than one type of power sources, operated together with associated

supporting equipment (including storage) to provide electric power to the grid or

on site. Hybridization through combining different energy sources in one supply

system offers the best possibility to use the system

APPLICATION OF HPS

HPS are an emerging technology for supplying electric power in remote locations. Off

grid renewable energy, technologies satisfy energy demand directly and avoid the

need for long distribution infrastructures. HPS can provide a steady community-level

electricity service, such as village electrification, offering also the possibility to be

upgraded through grid connection in the future. Due to their high levels of efficiency,

reliability and long term performance, HPS can also be used as an effective backup

solution: to the public grid in case of blackouts or weak grids; for professional energy

solutions, such as telecommunication stations or emergency rooms at hospitals.

ADVANTAGES vs. DISADVANTAGES OF HPS

Advantages:

Shelter consumers from temporary energy price volatilit created by supply and

demand mismatches. Increase the reliability of energy, thereby avoiding significant


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costs with power outages. Provide a cost-effective means to minimize the impact of

intermittent resources. Decrease environmental impacts of energy supply.

Disadvantages:

More complex design, therefore increased design effort and more complexity in

operation. More complex control systems are required for handling:

– power generation

– storage

– transmission

– usage options

higher costs


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1.1 PROBLEMS

There is no operational difficulty as such in a solar (SPV) system and hybrid solar

wind system. Only the solar panels need to be cleaned with water at regular intervals.

In case of a Wind Turbine Generator, the power generation depends on the wind

velocity. Thus restricted to locations where the annual average wind velocity is 4.5

m/s or higher. For the windmills, annual preventive maintenance is required for

optimal efficiency.

WORKING OF HYBRID ENERGY


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1.2 SCOPE & OBJECTIVES

This project determines the use of renewable resources in abundant. This covers the

charging of mobile phones in those areas where scarcity of electricity is the big

problem. The main objective of this project is to use wind & solar energy at the same

time in the form of hybrid energy output.

PROPOSED WORK

Solar panels & windmills are used separately for the generation. But it works together

with the help of Hybrid Solar System theory.

Renewable sources Installed Capacity Estimated Potential

Wind

Biomass Power/ Cogeneration

Biomass Gratifier

Small Hydro

Waste to Energy

Solar PV

2483 MW

613 MW

58 MW

1603 MW

41 MW

151 MW

45000 MW

19500 MW

—

15000 MW

1700 MW

20 MW/sq.km


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CHAPTER 2


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LITERATURE REVIEW

Those days we are using conventional fossil source coal, oil, natural gas and it have recently

entered into a quick decreasing tendency. Alternative and renewable energy sources have

importance more than fossil fuel sources in the human history. The price of fossil fuel is

increases because of the present energy production sources enter quickly into the exhaustion

tendency. It affects human health and environment.Countries tend to energy production

sources like the solar, hydrogen and wind which are not dependent on abroad in sense of

source. Also it is more sensitive to the environment and human health.


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2.1 SOLAR ENERGY SYSTEM:

In India the annual global solar radiation is about 5 KWh/ sq m per day with about

2300-3200 sun-shine hours per year. Solar radiations represent the earth’s most

abundant energy source. The perennial source of solar energy provides unlimited

supply, has no negative impact on the environment. The solar photovoltaic (PV)

modules convert solar radiation from the sun into electrical energy in the form of

direct current (DC). Converting solar energy into electricity is the answer to the

mounting power problems in the rural areas. Its suitability for decentralized

applications and its environment-friendly nature make it an attractive option to

supplement the energy supply from other sources. 1 KWp of SPV generates 3.5-4.5

units (Kwhr) per day.

2.1.2 If we could install Solar Photovoltaic Cells much of the rural exchange power

needs could be met, adequately cutting down harmful greenhouse gases.

There are two types of solar systems;

those that convert solar energy to D.C power, and those that convert solar energy

to heat.

Solar-generated Electricity – Photovoltaic

The Solar-generated electricity is called Photovoltaic (or PV). Photovoltaic are solar

cells that convert sunlight to D.C electricity. These solar cells in PV module are made

from semiconductor materials. When light energy strikes the cell, electrons are

emitted. The electrical conductor attached to the positive and negative scales of the

material allow the electrons to be captured in the form of a D.C current. The

generated electricity can be used to power a load or can be stored in a battery.

Photovoltaic system is classified into two major types: the off-grid (stand alone)

systems and inter-tied system. The off-grid (stand alone) system are mostly used

where there is no utility grid service. It is very economical in providing electricity at

remote locations especially rural banking, hospital and ICT in rural environments.

PV systems generally can be much cheaper than installing power lines and step-down

transformers especially to remote areas. Solar modules produce electricity devoid of

pollution, without odour, combustion, noise and vibration. Hence, unwanted nuisance


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is completely eliminated. Also, unlike the other power supply systems which require

professional training for installation expertise, there are no moving parts or special

repairs that require such expertise .

Basic Components of Solar Power

The major components include P.V modules, battery and inverter. The most efficient

way to determine the capacities of these components is to estimate the load to be

supplied. The size of the battery bank required will depend on the storage required,

the maximum discharge rate, and the minimum temperature at which the batteries will

be used [4]. When designing a solar power system, all of these factors are to be taken

into consideration when battery size is to be chosen.Lead-acid batteries are the most

common in P.V systems because their initial cost is lower and also they are readily

available nearly everywhere in the world.Deep cycle batteries are designed to be

repeatedly discharged as much as 80 per cent of their capacity and so they are a good

choice for power systems. Figure 2 is a schematic diagram of a typical Photovoltaic

System.

Photovoltaic (P.V) Solar Modules

The photovoltaic cell is also referred to as photocell or solar cell. The common

photocell is made of silicon, which is one of the most abundant elements on earth,

being a primary constituent of sand. A Solar Module is made up of several solar cells

designed in weather proof unit. The solar cell is a diode that allows incident light to

be absorbed and consequently converted to electricity. The assembling of several

modules will give rise to arrays of solar panels whose forms are electrically and

physically connected together. To determine the size of PV modules, the required

energy consumption must be estimated. Therefore, the PV module size in Wept is

calculated as Daily energy Consumption Isolation x efficiency Where Isolation is in


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KWh/m2/day and the energy consumption is in watts or kilowatts. Figure 2 is a

schematic diagram of a typical Photovoltaic System.

WORKING OF PV PANEL:

Batteries and Batteries Sizes of the Solar System

As mentioned above, the batteries in use for solar systems are the storage batteries,

otherwise deep cycle motive type. Various storage are available for use in

photovoltaic power system, The batteries are meant to provide backups and when the

radiance are low especially in the night hours and cloudy weather. The battery to be

used:

(a) Must be able to withstand several charge and discharge cycle

(b) Must be low self-discharge rate


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(c) Must be able to operate with the specified limits.

The battery capacities are dependent on several factors which includes age and

temperature. Batteries are rated in Ampere-hour (Ah) and the sizing depends on the

required energy consumption. If the average value of the battery is known, and the

average energy consumption per hour is determined. The battery capacity is

determined by the equations 2a and 2b.

BC = 2*f*W/Vbatt (2a)

Where BC – Battery Capacity

f – Factor for reserve

W – Daily energy

Vbatt – System DC voltage

The Ah rating of the battery is calculated as:

Daily energy Consumption (KW) (2b)

Battery rating in (Amp-hr) at a specified voltage

2.6 Ch.

Proposed Power System.


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PV Array constraints

Ep(t) is the sum of the energy supplied by the PV array to the loads and to the battery

bank, in hour t,

QP,B(t)+{∑iQ

P,i(t)}+Q

P,R(t)=E

P(t)

where,

QP,i (t) is the energy supplied by PV array to the

loads

QP,B (t) is the energy supplied by PV array to the

battery bank

QP,R (t) is the energy dumped by PV array

Since energy generated by the system varies with

insolation, therefore the available array energy

Ep(t) at any particular time is given by

where,

Ep(t)=VS(t) V is the capacity of PV array S(t) is the insolation index.


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Fig. 1. Solar Insolation In india


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Fig. 2. Annual Mean Daily Global Solar Electric Conversion Potential In

India(MW)


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2.2 WIND ENERGY SYSTEM:

Wind energy is another viable option. The Wind Turbine Generator is designed for

optimal operation at wind speed of 10-14 m/s. The Turbine Generator starts at a cut-in

speed of 3-3.5 m/s and generates power at speeds 4.5 m/s and above. In India, the best

wind speed is available during monsoon from May to September and low wind speed

during November to March. The annual national average wind speed considered is 5-

6 m/s. Wherever average wind speed of 4.5 m/s. and above is available it is also an

attractive option to supplement the energy supply. Wind generators can even be

installed on telecom tower at a height of 15-20 mt. with suitable modification in tower

design, taking into account tower strength.

Wind Power is energy extracted from the wind, passing through a machine known as

the windmill. Electrical energy can be generated from the wind energy. This is done

by using the energy from wind to run a windmill, which in turn drives a generator to

produce electricity. The windmill in this case is usually called a wind turbine. This

turbine transforms the wind energy to mechanical energy, which in a generator is

converted to electrical power. An integration of wind generator, wind turbine, aero

generators is known as a wind energy conversion system (WECS ).

Component of a wind energy

Modern wind energy systems consist of the following components:

A tower on which the wind turbine is mounted;

A rotor that is turned by the wind;

The nacelle which houses the equipment, including the generator that converts the

mechanical energy in the spinning rotor into electricity. The tower supporting the

rotor and generator must be strong. Rotor blades need to be light and strong in order

to be aerodynamically efficient and to withstand prolonged used in high winds.In


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addition to these, the wind speed data, air density, air temperature need to be known

amongst others.

Wind Turbine

A wind turbine is a machine for converting the kinetic energy in wind into mechanical

energy. Wind turbines can be separated into two basic types based on the axis about

which the turbine rotates. Turbines that rotate around a horizontal axis are more

common. Vertical-axis turbines are less frequently used. Wind turbines can also be

classified by the location in which they are used as Onshore, Offshore, and aerial

wind turbines.


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Turbine Components

Wind Turbine Subsystems and Components

Rotor

Drive Train

Yaw System

Main Frame

Tower

Control System


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Rotor: Hub

Hub connects the blades to the main shaft

Usually made of steel

Types

Rigid

Teetered

Hinged

Hub of 2 blade turbine

Fig:structure of ROTOR HUB

Blades


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Fig: structure of blade

Drive Train: Main Shaft

Main Shaft is principal rotating element, transfers torque from the rotor to the rest of

the drive train. Usually supports weight of hub. Made of steel.

Drive Train

Generator

Converts mechanical power to electricity

Couplings

Used to Connect Shafts, e.g. Gearbox High Speed Shaft to Generator Shaft.


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Drive Train: Gearbox

Gearbox increases the speed of generator input shaft

Main components: Case, Gears, Bearings

Types: i) Parallel Shaft, ii) Planetary

Typical Planetary Gearbox (exploded view)

Drive Train: Mechanical Brake

Mechanical Brake used to stop (or park) rotor

Usually redundant with aerodynamic brakes

Types:

Disc

Clutch

Location:

Main Shaft

High Speed Shaft


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Design considerations:

Maximum torque

Length of time required to apply

Energy absorption

Fig:disk brake

Main frame:

The main frame is the plateform to which the other principal components are attached.

Provides for proper alignment among those components. Provides for yaw bearing

and ultimately tower top attachment .usually made of cast or welded steel.

Nacelle Cover

The nacelle cover is the wind turbine housing.Protects turbine components from

weather.Reduces emitted mechanical sound.Often made of fiberglass.


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Fig: structure of Nacelle cover

Tower

Raises turbine into the air

Ensures blade clearance

Types

Free standing lattice (truss)

Cantilevered pipe (tubular tower)

Guyed lattice or pole.


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Fig: structure of tower

Cost of Energy

Cost of energy (COE), $/kWh

COE = (C*FCR+O&M)/E

Depends on:

Installed costs, C

Fixed charge rate, FCR – fraction of installed costs paid each year (including

financing)

O & M (operation & maintenance)

Annual energy production, E.

Typical Costs

Wind

Size range: 500 W- 2,000 kW

Installed system: $900-1500/kW

COE: $0.04 – 0.15/kWh


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Typical Energy Production

Use ‘Capacity Factor’ (CF)

CF = Actual Energy/Maximum Energy

E = CF x Rated Power x 8760 (kWh/yr)

Typical Range:

CF = 0.15 - 0.45

CF ideally > 0.25

Improvements to Economics

Increase efficiency

Some increase possible

Increase production

Use high wind sites, higher towers

Lower total costs

Design improvements, larger turbines

Increase value

RPS (Renewable Portfolio Standard), etc.

Wind Power Modeling

The block diagram in figure 3 shows the conversion process of wind energy to

electrical energy. Various mathematical models have been developed to assist in the

predictions of the output power production of wind turbine generators (WTG), A

statistical function known as Woefully distribution function has been found to be

more appropriate for this purpose. The function is used to determine the wind

distribution in the selected site of the case study and the annual/monthly mean wind

speed of the site. The woefully distribution function has been proposed as a more


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generally accepted model for this purpose. The two-parameter woefully distribution

function is expressed mathematically in equation 3 as.

F(v)=k/c(v/c)k-1 exp[-(v/c)k]……………………………..(3)

It has a cumulative distribution function as expressed in equation 4,and is given as:

M(v)=1-exp[-(v/c)k]……………………………………………..(4)

where v is the wind speed, K is the shape parameter and C, the scale parameter of the

distribution. The parameters K (dimensionless) and C (m/s) therefore characterized

the Wiebull distribution. To determine K and C, the approximations widely accepted

are given in equations 5 and 6 respectively.

K=(sigma/v’)-1.09 ……………………………………..(5)

C=v’*k2.6674/(0.184+0.186k2.73859) ………….(6)

Where sigma = standard deviation of the wind speed for the site (ms-1) .

V´ = mean speed (ms-1).


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Fig. 3. WIND MAP OF INDIA


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2.3 HYBRID ENERGY SYSTEM:

2.3.1 Hybrid Wind-Solar System for the rural exchanges can make an ideal alternative

in areas where wind velocity of 5-6 m/s is available. Solar-wind power generations

are clear and non-polluting. Also they complement each other. During the period of

bright sun-light the solar energy is utilized for charging the batteries, creating enough

energy reserve to be drawn during night, while the wind turbine produce most of the

energy during monsoon when solar-power generation is minimum. Thus the hybrid

combination uses the best of both means and can provide quality, stable power supply

for sustainable development in rural areas.

2.3.2 These systems are specifically designed to draw 48 volts DC power output from

the solar cells/ wind turbines and combine them to charge the storage batteries. The

system does require availability of diesel generator, though for much reduced number

of hour’s operation. It is also designed to give priority to solar and wind power so that

operations of generators can be minimized to the extent possible.

Hybrid power systems (HPS) are any autonomous electricity generating systems,

incorporating more than one type of power sources, operated together with associated

supporting equipment (including storage) to provide electric power to the grid or

on site. Hybridization through combining different energy sources in one supply

system offers the best possibility to use the system. Hybrid energy system isincluding

several (two or more) energy sources with appropriate energy conversion technology

connected together to feed power to local load/grid. Figure gives the general pictorial

representation of Hybrid energy system. Since, it is coming under distributed

generation umbrella, there is no unified standard or structure. It receives benefits in

terms of reduced line and transformer losses, reduced environmental


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Renewable sources Installed Capacity Estimated Potential

Wind

Biomass Power/ Cogeneration

Biomass Gratifier

Small Hydro

Waste to Energy

Solar PV

2483 MW

613 MW

58 MW

1603 MW

41 MW

151 MW

45000 MW

19500 MW

—

15000 MW

1700 MW

20 MW/sq.km

Table1:power generation from renewable source

impacts, relived transmission and distribution congestion, increased system reliability,

improved power quality, peak shaving, and increased overall efficiency.

Fig: power generation from hybrid energy system


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Fig. 4. BLOCK DIAGRAM: WIND/SOLAR HYBRID POWER SYSTEM

Fig:busbar structure

Major features of Hybrid energy system:

HES allow wide variety of primary energy sources, frequently renewable sources

Generation as the stand alone system for rural electrification where grid extension is

not possible or uneconomic. Design and development of various HES components

Has more flexibility for future extension and growth. Device can be added as the need

Arises and assure the promising operation with existing system. If there is excess


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Generation than demand, it can be feed in to grid which leads new revenue. The

―whole ―is worth more than the ―parts‖. Since many sources are involving in power

generation, its stability, reliability and efficiency will be high. Running cost of

thermal plant and atomic plant is high. Majority of the renewable source based

electricity generation has minimum running cost also abundant in nature .We have

developed a hybrid energy system, which is consisting of consisting of biomass, wind,

solar photovoltaic (SPV) and battery. Figure 2 shows the proposed hybrid energy

system model. The sources are operated to deliver energy at optimum efficiency. An

optimization model is developed to supply the available energy to the loads according

to the priority. It is also proposed to maintain fair level of energy storage to meet

thepeak load demand together with biomass, wind, solar photovoltaic, during low or

no solar radiation periods or during low wind Periods.

Barriers:

Maximum power extraction: When different V-I characteristics voltages are

connected

together, one will be superior to other. In this circumstance, extracting maximum

power is difficult for a constant load. Stochastic Nature of sources: These

Distributed sources are site specific and diluted. So, the design of power converters

and controllers has to design to meet the requirement. Complexities in matching

Voltage and frequency level of both inverted DC sources like PV system, fuel cell, etc

Controlled AC sources like wind, hydro, etc. Because, these sources V-I

characteristics

Depends on atmospheric condition, which is varying time to time. Forecasting of

these

Sources are not accurate.

Coordination: In order to get reliable power, these HES connected to utility grid.

Often

Frequency mismatch arises between both systems. Hence it leads instability of the

Overall system.

Energy Conversion Technology: Sun is the primary sources of all energies. It is

available in many ways like oil, coal, wind, hydel, sunlight. We are generating

electrical

energy from these sources directly or indirectly. So far, there is no unique viable

method is used for conversion and utilization.

Power Quality: Variety of power electronics converters are involved in the power

conditioning of hybrid energy system between sources to load. These power

converters generate many harmonic components to the load which cause various

disturbances to the load/power distribution system.

MODEL DEVELOPMENT The objective of the proposed optimization model is to optimize the availability of

energy to the loads according to their levels of priority. It is also proposed to maintain

a fair level of energy storage in battery to meet peak load demand (together with

the gasifier, wind and PV array), during low or noradiation periods and wind speed is

very less. Theloads are classified as primary and deferrable loads.It is desired to

minimize, dumped energy, Qdump(t). The dumped energy is the excess energy, or

energy which cannot be utilized by the loads.The objective function is to maximize


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24

∑{∑pl(t)-Qdump(t)}

withIi(t)≥0 where,t is hour of a particular day t = 1,2, …24

i is load type primary and deferrable loads

Qp,i(t)+Qw,i(t)+Qg,i(t)+QB,i(t)=Ii(t).Pi……..(2)

Pi is Demand of load i at time t in KW

Ii (t) is the fraction of time t that the load i is supplied energy

Load constraints

The energy distribution from the energy sources

at period t to each load i is given as Where QP, Qw,

QG, QB are the energy supplied by the PV, Wind,

Gasifier and Battery respectively.

PV Array constraints

Ep(t) is the sum of the energy supplied by the PV array to the loads and to the battery

bank, in hour t,

QP,B(t)+{∑iQ

P,i(t)}+Q

P,R(t)=E

P(t)

where,


loads


battery bank





where,

Ep(t)=VS(t) V is the capacity of PV array S(t) is the insolation index.

where,


loads


battery bank





where,

(4)

V is the capacity of PV array


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S(t) is the insolation index

Wind energy system constraints

EW(t) is the sum of the energy supplied by the wind

energy system to the loads and battery bank at hour t,

where,

Qw,i(t) is the energy supplied by the wind energy

system

Qw,B(t) is the energy supplied by the wind energy

system to the battery bank

Qw,R(t) is the dumped energy by the wind energy

System.

Battery bank constraints The battery bank serves as an energy source entity when discharging and a load when

charging. The net energy balance to the battery determines it’s state-of-charge, (SOC)

The state of charge is expressed as follows

Where QB is the capacity of the battery bank The battery has to be protected against

overcharging; therefore, the charge level at (t-1) plus the influx of energy from the

PV, wind and gasifier at period (t-l), (t) should not exceed the capacity of the battery.

Mathematically

It is also necessary to guard the batteryagainst excessive discharge. Therefore the

SOC at any period t should be greater than a specified minimum SOC, SOCmin

Dumped energy

From the above equations the total dumped energy in each hour t as follows

Maximum power point tracking of PV array and wind system are developed in our campus to

harvest maximum energy form the source.


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Peak power point tracking of pv array:

Peak power point tracking of PV array fed induction motor drive is developed in our campus.

This system shown in figure 3 consists of PV array, DC chopper, inverter, microcontroller unit

andsingle-phase capacitor run induction motor drive. PV array is providing electricity to the load

through the power conditioning circuits respectively chopper and inverter. Microcontroller is

incorporated with the proposed system in closed loop operation to generate firing pulses for both

chopper and inverter in order to track peak power point. Dedicated software is developed for the firing

pulse generation in MPLAB platform and tested successfully in PROTEUS software, whichFigure 3

DECEMBER 2009 7 is made especially for microcontroller-based applications. The proposed system is

simulated in MATLAB/SIMULINK platform and the performances are computed. Figure 3 shows the

simulated model of the proposed system. The fabrication work is carried out for the proposed system

and tested successfully in Electrical lab.


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Fig: Available Photovoltaic power

Figure: Response of Drive system during for different solar insulation and

atmospheric temperature

Peak power Point Tracking of Wind Generator:

Wind energy is transformed into mechanical energy by means of a wind turbine that has one or several

blades. The turbine coupled to the generator by means of a mechanical drive train. The speed and

direction of the wind impinging upon a wind turbine is constantly changing. Over any given time

interval, the wind speed will fluctuate about some mean value. The power obtained by the turbine is

a function of wind speed. This function may have a shape such as shown in Figure.


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Peak power point tracking of wind generator isdeveloped in our campus. This system

consists of wind generator, DC chopper, microcontroller unit.Wind generator is

providing electricity to the load through the power conditioning circuit (chopper).

Microcontroller is incorporated with the proposed system in closed loop operation to

generate firing pulses for chopper in order to track peak power point.

.

Fig: Hourly wind speed and wind power at the site


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Fig: Hourly solar radiation and solar power at the site

Fig.22 Load Demand for a typical day

ECONOMIC ANALYSIS

With the data collected from the site, a detailed economic analysis has been carried

out using micro power optimization software homer. The results are presented in this

section. Fig.7 shows the monthly average contributions of the different sources and

the utility grid. It shows that the variation is not only in the demand but also the

availability of sources. The utility compensates the shortage.


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Fig. Monthly average power from hybrid energy system

Fig. shows the annual contribution of the sources in hybrid energy system and utility

grid. The total energy from the PV system is 307,089kWh. It is about 22 % of the

total energy supplied to the load by the hybrid energy system. It is found that the total

energy from the wind is 398,514kWh. It is about 29 % of the total energy supplied to

the load by the hybrid energy system. The biomass gasifier supplies the remaining

energy, which is 516,750kWh. It is about 37 % of the total energy supplied to the load

by the hybrid energy system. The grid contributes about 12% of the demand.

Fig.9 shows the total monthly purchase and saleof energy with the utility grid. The

total annual energy drawn from the grid is 163,344 kWh and fed into the grid is

90,679 kWh.

Fig.8 Annual Contribution of different sources and grid


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Fig: Monthly feeding and drawing of energy from the utility grid


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CHAPTER 3


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METHODOLOGY & IMPLEMENTATION

3.1 METHODOLOGY:

In order to address the shortcomings Of existing instructional techniques For

electrical power systems, a Hybrid wind-turbine and solar cell System has been

implemented at the University of Northern Iowa. The System was designed and

implemented with the following goals: To be completely different from Traditional

electricity labs and toBe fresh and interesting. To be intimately related to real world

Industrial power issues such as power quality. To show a complex, interrelated system

that is closer to the ―real world‖ than the usual simple.


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3.2 IMPLEMENTATION

APPROPRIATE GEOGRAPHICAL REGION:

Solar

In India, the annual average solar radiation of 5 KW h/sq m per day with about 2300-

3200 sunshine hours per year is available in most parts of the country except some

pockets in north-east. As such solar power (SPV) decentralized system can be

considered for the telecommunication network in rural areas in most parts of the

country.

Wind

The southern and western coastal areas are the ideal location for wind generators. For

the telecommunication network in rural areas in states like Tamil Nadu, Karnataka,

Gujarat, Maharashtra and parts of Orissa, Andhra Pradesh, Madhya Pradesh where the

annual average wind speed of 5-6 m/s is available, installation of hybrid solar-wind

power system can be an attractive option to supplement the energy supply.

MODEL OF SOLAR/WIND HYBRID ENERGY SYSTEM

In the controller unit, we implement one mobile charging cable & one digital clock

with temperature measurement features.


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CHARGING ELECTRONICS (CONTROLLERS)

The need for Charging Controllers is very important so that overcharging of the

batteries can be prevented and controlled. The controllers to be used required the

following features:

Prevent feedback from the batteries to PV modules. It should have also a connector

for DC loads. It should have a work mode indicator.


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CHAPTER 4


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RESULTS

Choice of components for Solar Energy Power Supply For 10 Watt Load: The choice

of 10W is a sample case and this can be extended to any required capacity. To achieve

a solar power capacity of 10watts the capacities of Solar panel, Charging Controller,

bank of battery and Inverter are determined. The values cannot be picked abstractly

and hence, their ratings and specification have to be determined through calculations

in other for the system to perform to required specifications.


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OUTPUT

WIND

Current=2A

Voltage=12V

SOLAR

Current=2*1.5A=3A

Power=2*5W=10W

Voltage=12V

HYBRID OUTPUT

Current=4.8A (approx. 5A)

Voltage=12V.


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CHAPTER 5

CONCLUSIONS & FUTURE WORKS


- 50 -

5.1 CONCLUSIONS:

Obviously, a complete hybrid power system of this nature may be too expensive &

too labour intensive for many industrial technology departments. However, many of

the same benefits could be gleaned from having some subset of the system. For

example, a PV panel, batteries & an inverter, or just a PV panel & a DC motor. The

enhancement to instruction, especially in making electrical power management. More

physical intuitive & real world are substantial & the costs & labour involved in some

adaptation of the ideas in in this paper to a smaller scale setup are reasonable.The use

of Solar & Wind hybrid power generation is an especially vivid & relevant choice for

students of electrical technology as these are power source of technological, political

& economic importance in a country.

5.2 FUTURE WORK:

A computer measurement and control bus will be added to the system. Computer

controlled relays will be added to allow all the major elements of the system to be

switched in and out of the system through computer programs. The measurement bus

will be connected to all the major signals in the system and will allow for


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computerizes data acquisition simultaneously of all the major signals in the system.

These improvements will allow for the study of more complex issues like power

faults caused by sudden over voltages like lightning. These improvements will also

allow the same benefits to instruction realized in electricity and electronics classes to

be extended to control and instrumentation classes.

REFERENCES

[1] N. Kodama, T. Matzuzaka, and N. Inomita, ―Power Variation Control of a Wind

Turbine Using Probabilistic Optimal Control, Including Feed-forward Control for

Wind Speed,‖ Wind Eng., Vol. 24, No. 1, 13 – 23, Jan 2000.


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[2] L. L. Freris, Wind Energy Conversion Systems, Englewood Cliffs, NJ: Prentice-

Hall, 182 – 184, 1990.

[3] E. Koutroulis and K. Klaitzakis, ― Design of a Maximum Power Tracking System

for Wind-Energy-Conversion Applications,‖ IEEE Trans. on Indust. Elect., Vol. 53,

No. 2, 2006, 486 – 494, April.

[4] E. Muljadi and C. P. Butterfield, ―Pitch-controlled Variable- speed Wind Turbine

Generation,‖ IEEE Trans. Ind. Appl., Vol. 37, No. 1, 2001, 240 – 246.

[5] W. Lin, H. Matsuo, and Y. Ishizuka, ―Performance Characteristics of Buck-Boost

Type Two-input DC-DC Converter With an Active Voltage Clamp,‖ IEICE Tech.

Rep., Vol. 102, No. 567, 2003, 7 – 13.

[6] J. A. Baroudi, V. D. Dinavahi, and A. M. Knight, “A review of Power Converter

Topologies for Wind Generators,” Renewable Energy 32, Science Direct, January,

2007, 229 – 2385.

[7] Z. Chen and E. Spooner, ―Current Source Thyristor Inverter and its Active

Compensation System,‖ Proceedings of IEE Generation, Transmission, and

Distribution, Vol. 150 , 2003, 447 – 454.

[8] K. Tan and S. Islam, ―Optimum Control Strategies in Energy Conversion of

PSMG Wind Turbine System Without Mechanical Sensors,‖ IEEE Trans Energy

Convers, Vol. 10, 2004, 392 – 399.

[9] Z. Chen and E. Spooner, ―Grid Power Quality with Variable Speed Wind

Turbines,‖ IEEE Trans Energy Convers, Vol. 16, 2001, 148 – 154.

[10] Z. Chen and E. Spooner, ―Wind Turbine Power Converters: A comparative

Study,‖ Proceedings of IEE Seventh International Conference on Power Electronics

and Variable Speed Drives, 1998, 471 – 476

Final Year Project WSE

Documents

Transcript of Final Year Project WSE