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A

Project Report

On

SINGLE PHASE INVERTER

Under the guidance of

Ms. Ritu Jain

Submitted in partial fulfillment for the Award of degree of

BACHELOR OF TECHNOLOGY

IN

ELECTRICAL ENGINEERING

Department of Electrical Engineering

SURESH GYAN VIHAR UNIVERSITY, JAIPUR

Submitted To: - Submitted By:-

Mr. Rahul Sharma Kishan Kumar Yadav

Asst. Professor Mahipal Singh Shaktawat

Dept. of Electrical Engineering NischalDattatreya

Nitesh Kumar

3rd year (VI Sem.)

DEPARTMENT OF ‘ELECTRICAL ENGINEERING’

SURESH GYAN VIHAR UNIVERSITY,JAIPUR

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SINGLE PHASE INVERTER

Submitted by

S.No. Name of Students Enrolment No.

1. Kishan Kumar Yadav sgvu111055594

2. Mahipal Singh Shaktawat sgvu111055284

3. NischalDattatreya sgvu111055262

4. Nitesh Kumar sgvu111055292

Department of electrical engineering

GyanVihar School of Engineering & Technology

SURESH GYAN VIHAR VNIVERSITY

JAIPUR

April, 2014

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S.No. Name of Students Enrolment No.

1. Kishan Kumar Yadav sgvu111055594

2. Mahipal Singh Shaktawat sgvu111055284

3. NischalDattatreya sgvu111055262

4. Nitesh Kumar sgvu111055292

Submitted to the

Department of Electrical Engineering

In partial fulfillment of the requirements

For the degree of

Bachelor of Technology

In

Electrical Engineering

GyanVihar School of Engineering & Technology

SURESH GYAN VIHAR UNIVERSITY

JAIPUR

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April, 2014

CERTIFICATE

This is to certify that Project Report entitled “SINGLE PHASE INVERTER” which is

submitted by Kishan Kumar Yadav, Mahipal Singh Shaktawat, NischalDattatreya

and Nitesh Kumar in partial fulfillment of requirement for the award of B. Tech. degree

in department of Electrical Engineering is a record of the candidates own work carried

out by him/them under my/our supervision. The matter embodied in this thesis is

original and has not been submitted for the award of any other degree.

Signature

Name of Supervisor Ms. Ritu Jain

Designation Asst. Professor

Date

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DECLARATION

I/we hereby declare that this submission is my/our own work and that, to

the best of my/our knowledge and belief, it contains no material previously

published or written by another person nor material which to a substantial

extent has been accepted for the award of any other degree or diploma of the

university or other institute of higher learning except where due

acknowledgment has been made in the text.

Signature Signature

Name Kishan Kumar Yadav Name Mahipal Singh Shaktawat

Enrolment No. Sgvu111055594 Enrolment No. Sgvu111055284

Date Date

Signature Signature

Name NischalDattatreya Name Nitesh Kumar

Enrolment No. Sgvu111055262 Enrolment No. Sgvu111055292

Date Date

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ACKNOWLEDGEMENT

It gives us a great sense of pleasure to present the report of the B. Tech

project undertaken during B. Tech Pre final year. We owe special debt of

gratitude to Ms. Ritu Jain for his constant support and guidance throughout

the course of our work. His sincerity, thoroughness and perseverance have

been a constant source of inspiration for us. It is only his cognizant efforts

that our endeavors has been light of the day.

We also take the opportunity to the acknowledge the contribute of

Mr. R.K.Gupta Head of department of Electrical Engineering for his full

support and during the development of the project. We also do not like to

miss the opportunity to acknowledge the contribut e of all faculty members

of the department for their kind assistance and cooperation during the

development of our project. Last but not the least, we acknowledge our

friends for their contribute in the completion of the project.

Signature Signature

Name Kishan Kumar Yadav Name Mahipal Singh Shaktawat

Enrolment No. Sgvu111055594 Enrolment No. Sgvu111055284

Date Date

Signature Signature

Name NischalDattatreya Name Nitesh Kumar

Enrolment No. Sgvu111055262 Enrolment No. Sgvu111055292

Date Date

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CONTENT

CHAPTER NO. TOPIC PAGE NO.

01. INTRODUCTION 8-9

02. COMPONENT SPECIFICATION 10

03. POWER SUPPLY 11-13

3.1) Solar Plate

3.2) Working of Solar Panels

04. INVERTER 14-22

4.1) Single Phase Half Wave Inverter

4.2) Single Phase Full Wave Inverter

4.3) Square Wave Inverter

4.4) PWN control strategy

4.4.1) Amplitude & Harmonics Control

4.4.2) Sinusoidal Pulse Width Modulation (SPWM)

05. RESISTANCE 23-25

5.1)Resistivity of a conductor

5.2) Resistor Color Coding

06. CAPACITOR 26-28

6.1)Capacitor Color Coding

07. INDUCTOR COIL 29-30

08. TRANSISTOR 31-32

09. TRANSFORMER 33-34

9.1) EHT

9.2) Application

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CHAPTER 1

INTRODUCTION

Single phaseInverter :-

The dc-ac converter, also known as the inverter, converts dc power to ac power

at desired output voltage and frequency. The dc power input to the inverter is

obtained from an existing power supply network or from a rotating alternator

through a rectifier or a battery, fuel cell, photo voltaic array or magneto

hydrodynamic generator. The filter capacitor across the input terminals of the

inverter provides a constant dc link voltage. The inverter therefore is an

adjustable-frequency voltage source. The configuration of ac to dc converter

and dc to ac inverter is called a dc link converter.

Inverters can be broadly classified into two types, voltage source and

current source inverters. A voltage–fed inverter (VFI) or more generally a

voltage–source inverter (VSI) is one in which the dc source has small or

negligible impedance. The voltage at the input terminals is constant. A current–

source inverter (CSI) is fed with adjustable current from the dc source of high

impedance that is from a constant dc source.

A voltage source inverter employing thyristors as switches, some type of

forced commutation is required, while the VSIs madeup of using GTOs, power

transistors, power MOSFETs or IGBTs, self commutation with base or gate

drive signals for their controlled turn-on and turn-off.

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A standard single-phase voltage or current source inverter can be in the half-

bridge or full-bridge configuration. The single-phase units can be joined to have

three-phase or multiphase topologies. Some industrial applications of inverters

are for adjustable-speed ac drives, induction heating, standby aircraft power

supplies, UPS (uninterruptible power supplies) for computers, HVDC

transmission lines etc.

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CHAPTER-2

COMPONENT SPECIFICATION

Serial No. Components Ratings Quantity

1. Resistance 330 Ω 1

2. Capacitor

(electrolytic)

100µf/25v 1

3. Capacitor

(tantalum)

0.1µf/35v

2

4. Inductor Coil 10 mH 1

5. EHT(Boost

transformer)

12-0-12/500 mA 1

6. Zero PCB - 1

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CHAPTER-3

POWER SUPPLY

There are many types of DC power supply like a battery, fuel cell,

photovoltaic array or magneto hydrodynamic generator. Here we are using solar

plates or photovoltaic array as a power supply.

3.1)Solar plate: -

Solar plate is a light sensitized steel backed polymer material used by artists as

an alternative to hazardous printing techniques. It is a simple, safer, and faster

approach than traditional etching and relief printing.

It may be done by working on the plate directly, with opaque materials in the

form of non-water based pigments, or it may be utilized by exposing the plate

through a transparent film with artwork on it. The film may be created by

drawing on acetate, photocopying or scanning and printing on film, or darkroom

techniques. A positive transparency is for printing as an etching A negative

transparency is for printing a relief impression.

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3.2)Working of Solar Panels: -

A study of photo

voltage was made for a series of sandwich structures on the basis of poly(3-

dode-cylthiophene) films having characteristic thicknesses 100 and 500 nm and

being deposited on n-Si and p-Si substrates from a solution. Semi-transparent Al

and Au electrodes were obtained on the surfaces of these films by thermal

evaporation. A clear photo response was obtained in films on an n-Si substrate.

Two distinct spectral components of the photo voltage were observed in the 1.3-

to 3.6-eV (900–300 nm) energy range for incident quanta. The first component

corresponds to the absorption edge of the Si substrate (1.4–1.6eV). The other

corresponds to the π-π* absorption of the polythiophene films (1.7–2.1eV).

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The dependences of the photo voltage upon radiation intensity are different for

these two spectral components. The relaxation time of the photo response for

the second component, corresponding to the absorption in the film, is 10–20

min. This is 3–4 orders of magnitude higher than the relaxation time for the first

component. A model of the potential barrier at the polythiophene/n-Si interface,

allowing one to explain the main experimental results, is proposed. This barrier

is formed as a result of the chemical interaction of the polythiophene molecules

with the substrate.

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CHAPTER-4

INVERTER

An Inverter is basically a converter that converts DC-AC power. Inverter

circuits can be very complex so the objective of this paper is to present some of

the inner workings of inverters without getting lost in some of the fine details.

A voltage source inverter (VSI) is one that takes in a fixed voltage from a

device, such as a dc power supply, and converts it to a variable-frequency AC

supply.

Voltage-source inverters are divided into three general categories: Pulse-width

Modulated (PWM) Inverters, Square-wave Inverters, Single-phase Inverters

with Voltage Cancellation. Pulse-width modulation inverters take in a constant

dc voltage. Diode-rectifiers are used to rectify the line voltage, and the inverter

must control the magnitude and the frequency of the ac output voltages. To do

this the inverter uses pulse-width modulation using it’s switches. There are

different methods for doing the pulse-width modulation in an inverter in order

to shape the output ac voltages to be very close to a sine wave.

4.1) Single Phase Half Bridge Inverter

There are 2 switches by dividing the dc source voltage into two parts with

the capacitors.

Each capacitor has the same value and has voltage Vdc / 2.

The top(S1) and bottom(S2) switch must be complementary to each

other. (When S1 is closed, S2 must be opened and vice versa)

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Feedback (freewheeling) diodes are required to provide continuity of

current for inductive loads.

It provides current to flow even switches are opened.

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4.2) Single Phase Full Bridge Converter

Full bridge converter is also basic circuit to convert dc to ac.

An ac output is synthesized from a dc input by closing and opening

switches in an appropriate sequence.

There are also four different states depending on which switches are

closed.

State Switches Closed

Vo

1 S1 & S2 + Vdc

2 S3 & S4 -Vdc

3 S1 & S3 0

4 S2 & S4 0

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State 1 and State 2

State 3 and State 4

Switches S1 and S4 should not be closed at the same time. S2 and S3

should be closed in parallel too otherwise, a short circuit would exist

across the dc source.

Real switches do not turn on or off instantaneously. Hence, switching

transition times must be accommodated in the control of switches.

Overlap of switch "on" will cause short circuit (shoot-through fault)

across the dc voltage source.

The time allowed for switching is called blanking time.

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4.3) Square-wave Inverter

The figure below is the simple square-wave inverter to show the concept of

AC waveform generation.

The current waveform in the load depends on the load components.

The current waveform matches the shape of the output voltage for

the resistive load.

The current will have more sinusoidal quality than the voltage for

the inductive load because of the filtering property of the

inductance.

For a series RL load and a square wave output voltage, switches S1

and S2 is assumed to be closed at t = 0.

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4.4) PWM Control Strategy

There are several methods of controlling single phase inverter. However, these

are few criteria that we need to look at:

1. Output voltage range

2. Maximum output voltage

3. Switching losses

4. Distortion in output and input sides ( Distortion is measured based on

inverter performance)

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Pulse Width Modulation (PWM)

PWM provides a way to decrease the total harmonic distortion of load

current.

Generally, THD requirements is met easily than the square wave

switching scheme for PWM inverter output after filtering.

The unfiltered PWM output will have a relatively high THD. But, it can

be filtered easily due to high frequencies of harmonics.

There are two main types of PWM control strategy

4.4.1) Amplitude & Harmonics Control

Amplitude of the output voltage can be controlled with the modulating

waveforms.

Harmonics can be decreased and output voltage amplitude can be

controlled with the reduced filter requirements.

But, control circuits for the switches is complex, losses increase due to

more frequent switching.

The amplitude of the fundamental frequency for a square wave output

from the full bridge inverter is determined by dc input voltage.

The switching scheme can be modified to produced a controlled output.

An output voltage has intervals when the output is zero , + Vdc and -

Vdc.

The output voltage can be controlled by adjusting the interval α on each

side of the pulse where the output is zero.

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α is the angle of zero voltage on each end of the pulse.

The amplitude of the fundamental frequency (n=1) is controllable by

adjusting α.

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Harmonic content can be eliminated by adjusting α. Harmonic n is

eliminated if α = 90 0 /n

Note:To control both amplitude and harmonics using the switching

scheme, it is necessary to be able to control the dc input voltage to the

inverter.

4.4.2) Sinusoidal Pulse Width Modulation (SPWM) - Bipolar & Unipolar switching

Control of the switches for sinusoidal PWM output requires:

reference signal (modulating or control signal) - sinusoid in the case we

are going to learn

carrier signal (triangular wave that controls the switching frequency)

Sinusoidal Pulse Width Modulation (SPWM)

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CHAPTER-5

RESISTANCE

The electrical resistance of an electrical conductor is the opposition to the

passage of an electrical current through that conductor. The inverse quantity

is electrical conductance, the ease with which an electric current passes.

Electrical resistance shares some conceptual parallels with the mechanical

notion of friction. The SI unit of electrical resistance is the ohm, while electrical

conductance is measured.

An object of uniform cross section has a resistance proportional to its resistivity

and length and inversely proportional to its cross-sectional area. All materials

show some resistance, except for semiconductor which have a resistance of

zero.

The resistance (R) of an object is defined as the ratio of voltage across it (V) to

current through it (I), while the conductance (G) is the inverse:

R=V/I

5.1)Resistivity of a conductor

The resistance of a given object depends primarily on two factors: What

material it is made of, and its shape. For a given material, the resistance is

inversely proportional to the cross-sectional area; for example, a thick copper

wire has lower resistance than an otherwise-identical thin copper wire. Also, for

a given material, the resistance is proportional to the length; for example, a long

copper wire has higher resistance than an otherwise-identical short copper wire.

The resistance R and conductance G of a conductor of uniform cross section,

therefore, can be computed as

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where is the length of the conductor, measured in meters [m], A is the cross-

section area of the conductor measured in square matrix [m²], σ (sigma) is

the electrical conductivity measured in per meter (S·m−1), and ρ is the electrical

resistivity(also called specific electrical resistance) of the material, measured in

ohm-metres(Ωm). The resistivity and conductivity are proportionality constants,

and therefore depend only on the material the wire is made of, not the geometry

of the wire. Resistivity and conductivity are reciprocal Resistivity is a measure

of the material's ability to oppose electric current.

Resistence of 330 ohm(Ω)

5.2)Resistor color-coding

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To distinguish left from right there is a gap between the C and D bands.

band A is first significant figure of component value (left side)

bandB is the second significant figure (Some precision resistors have a

third significant figure, and thus five bands.)

band C is the decimal multiplier

bandD if present, indicates tolerance of value in percent (no band means

20%)

Color Significant

figures Multiplier Tolerance

Temp. Coefficient

(ppm/K)

Black 0 ×100 – 250 U

Brown 1 ×101 ±1% F 100 S

Red 2 ×102 ±2% G 50 R

Orange 3 ×103 – 15 P

Yellow 4 ×104 (±5%) – 25 Q

Green 5 ×105 ±0.5% D 20 Z

Blue 6 ×106 ±0.25% C 10 Z

Violet 7 ×107 ±0.1% B 5 M

Gray 8 ×108 ±0.05% (±10%) A 1 K

White 9 ×109 – –

Gold – ×10-1 ±5% J –

Silver – ×10-2 ±10% K –

None – – ±20% M –

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CHAPTER-6

CAPACITOR

A capacitor (originally known as a condenser) is a passive two- terminal

electrical component used to store energy electrostatically in an electric field.

The forms of practical capacitors vary widely, but all contain at least

two electrical conductors (plates) separated by a dielectric (i.e., insulator). The

conductors can be thin films of metal, aluminium foil or disks, etc. The ' non

conducting' dielectric acts to increase the capacitor's charge capacity. A

dielectric can be glass, ceramic, plastic film, air, paper, mica, etc. Capacitors are

widely used as parts of electrical circuit in many common electrical devices.

Unlike a resistor, a capacitor does not dissipate energy. Instead, a capacitor

stores energy in the form of an electrostatic field between its plates.

electolytic capacitor (100µf/25v)

When there is a potential difference across the conductors (e.g., when a

capacitor is attached across a battery), an electric field develops across the

dielectric, causing positive charge (+Q) to collect on one plate and negative

charge (-Q) to collect on the other plate. If a battery has been attached to a

capacitor for a sufficient amount of time, no current can flow through the

capacitor. However, if an accelerating or alternating voltage is applied across

the leads of the capacitor, a displacement current can flow.

An ideal capacitor is characterized by a single constant value for its capacitance.

Capacitance is expressed as the ratio of the electric charge (Q) on each

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conductor to the potential difference (V) between them. The SI unit of

capacitance is the FARAD (F), which is equal to one coulomb per volt (1 C/V).

Typical capacitance values range from about 1 pF (10−12 F) to about 1 mF

(10−3 F).

The capacitance is greater when there is a narrower separation between

conductors and when the conductors have a larger surface area. In practice, the

dielectric between the plates passes a small amount of leakage current and also

has an electric field strength limit, known as the breakdown voltage. The

conductors and leads introduce an undesired inductance and resistance.

A capacitor consists of two conductors separated by a non-conductive region.

The non-conductive region is called the dielectric. In simpler terms, the

dielectric is just an electrical insulator. Examples of dielectric media are glass,

air, paper and even a semiconductor depletion layer chemically identical to the

conductors. A capacitor is assumed to be self-contained and isolated, with no

net and no influence from any external electric field. The conductors thus hold

equal and opposite charges on their facing surfaces and the dielectric develops

an electric field. In SI units, a capacitance of one farad means that

one coulomb of charge on each conductor causes a voltage of one volt across

the device.

An ideal capacitor is wholly characterized by a constant capacitance C, defined

as the ratio of charge ±Q on each conductor to the voltage V between them.

6.1)Capacitor color-coding

Capacitors may be marked with 4 or more colored bands or dots. The colors

encode the first and second most significant digits of the value, and the third

color the decimal multiplier in picofarads. Additional bands have meanings

which may vary from one type to another. Low-tolerance capacitors may begin

with the first 3 (rather than 2) digits of the value. It is usually, but not always,

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possible to work out what scheme is used by the particular colors used.

Cylindrical capacitors marked with bands may look like resistors.

Color Significant

digits Multiplier

Capacitance

tolerance Characteristic

DC

working

voltage

Operating

temperature

EIA/vibration

Black 0 1 ±20% — — −55 °C to +70

°C 10 to 55 Hz

Brown 1 10 ±1% B 100 — —

Red 2 100 ±2% C —

−55 °C to +85

°C —

Orange 3 1000 — D 300 — —

Yellow 4 10000 — E —

−55 °C to

+125 °C

10 to

2000 Hz

Green 5 100000 ±0.5% F 500 — —

Blue 6 1000000 — — —

−55 °C to

+150 °C —

Violet 7 10000000 — — — — —

Grey 8 — — — — — —

White 9 — — — — — EIA

Gold — — ±5%* — 1000 — —

Silver — — ±10% — — — —

CHAPTER-7

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INDUCTOR COIL

An inductor is a passive electronic component which is capable of storing

electrical energy in the form of magnetic energy. Basically, it uses a conductor

that is wound into a coil, and when electricity flows into the coil from the left to

the right, this will generate a magnetic field in the clockwise direction.

Presented below is the equation that represents the inductance of an inductor.

The more turns with which the conductor is wound around the core, the stronger

the magnetic field that is generated. A strong magnetic field is also generated by

increasing the cross-sectional area of the inductor or by changing the core of the

inductor.

The current level remains unchanged when DC (direct current) flows to the

inductor so no induced voltage is produced, and it is possible to consider that a

shorted state results. In other words, the inductor is a component that allows

DC, but not AC, to flow through it.

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• The inductor stores electrical energy in the form of magnetic energy.

• The inductor does not allow AC to flow through it, but does allow DC to

flow through itthe properties of inductors are utilized in a variety of different

applications. There are many and varied types of inductors in existence.

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CHAPTER-8

TRANSISTOR

A transistor is a semiconductor device used to amplify and switchelectronic

signals and electrical power. It is composed of semiconductor material with at

least three terminals for connection to an external circuit. A voltage or current

applied to one pair of the transistor's terminals changes the current through

another pair of terminals. Because the controlled (output) power can be higher

than the controlling (input) power, a transistor can amplify a signal.

There are two types of transistors, which have slight differences in how they are

used in a circuit. A bipolar transistor has terminals labelledbase, collector, and

emitter. A small current at the base terminal (that is, flowing between the base

and the emitter) can control or switch a much larger current between the

collector and emitter terminals. For a field-effect transistor, the terminals are

labelledgate, source, and drain, and a voltage at the gate can control a current

between source and drain.

The image to the right represents a typical bipolar transistor in a circuit. Charge

will flow between emitter and collector terminals depending on the current in

the base. Because internally the base and emitter connections behave like a

semiconductor diode, a voltage drop

develops between base and emitter

while the base current exists. The

amount of this voltage depends on

the material the transistor is made

from, and is referred to as VBE.

PNP

P-channel

NPN

N-channel

BJT

JFET

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Transistor packages are made of glass, metal, ceramic, or plastic. The package

often dictates the power rating and frequency characteristics. Power transistors

have larger packages that can be clamped to heat sinks for enhanced cooling.

Additionally, most power transistors have the collector or drain physically

connected to the metal enclosure. At the other extreme, some surface-mount

microwave transistors are as small as grains of sand.

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CHAPTER-9

TRANSFORMER

A transformer is a static electrical device that transfers energy by inductive

coupling between its winding circuits. A varying current in the primary winding

creates a varying magnetic flux in the transformer's core and thus a varying

magnetic flux through the secondary winding. This varying magnetic flux

induces a varying electromotive force (emf) or voltage in the secondary

winding. Transformers range in size from thumbnail-sized used in microphones

to units weighing hundreds of tons interconnecting the power grid. A wide

range of transformer designs are used in electronic and electric power

applications. Transformers are essential for the transmission, distribution, and

utilization of electrical energy.

9.1)EHT (transformer)

A boost (EHT) transformer is a type of transformer used to make adjustments

to the voltage applied to alternating current equipment. The boost connections

are used in several places such as uninterrupted power supply (UPS) units for

computers, and in the tanning bed industry. Operating electrical equipment at

other than its designed voltage may result in poor performance, short operating

life, or possibly overheating and damage.

Buck–boost transformers can be used to power low voltage circuits including

control, lighting circuits, or applications that require 12, 16, 24, 32 or 48 volts,

consistent with the design's secondaries. The transformer is connected as an

isolating transformer and the nameplate kVA rating is the transformer’s

capacity.

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9.2)Application

Buck-boost transformers may be used for electrical equipment where the

amount of buck or boost is fixed. For example, a fixed boost would be used

when connecting equipment rated for 230 V AC to a 208 V power source.

Units are rated in volt-amperes (or more rarely, amperes) and are rated for a

percent of voltage drop or rise. For example, a buck–boost transformer rated at

10% boost will raise a supplied voltage of 208 V AC to 229 V AC. A rating of

10% buck will yield the result of 209 V AC if the actual incoming supplied

voltage is 230 V AC.

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Working of single phase inverter:-

One of the most incredible things about photovoltaic power is its simplicity. It is almost

completely solid state, from the photovoltaic cell to the electricity delivered to the

consumer. Whether the application is a solar calculator with a PV array of less than 1 W

or a 100 MW grid-connected PV power generation plant, all that is required between the

solar array and the load are electronic and electrical components. Compared to other

sources of energy humankind has harnessed to make electricity, PV is the most scalable

and modular. Larger PV systems require more electrical bussing, fusing and wiring, but

the most complex component between the solar array and the load is the electronic

component that converts and processes the electricity: the inverter.

In the case of grid-tied PV, the inverter is the only piece of electronics needed between

the array and the grid. Off-grid PV applications use an additional dc to dc converter

between the array and batteries and an inverter with a built-in charger. In this article we

discuss how inverters work, including string, or single-phase, and central, 3-phase

inverters; explore major inverter functions, key components, designs, controls,

protections and communication; and theorize about future inverter technology.

Reference:

www.google.com

http//www.indiastudychannel.com