The document is a major project report focused on the design and development of a pure sine wave inverter aimed at efficiently converting DC power sources into high voltage AC outputs. It documents the process, objectives, and methodology utilized by the students under the guidance of their supervisor at the National Institute of Technology, Uttarakhand. The project addresses the need for reliable power solutions in light of frequent power outages and emphasizes the importance of pure sine wave inverters for running sensitive electronic devices.

1. i
DESIGN AND DEVELOPMENT OF PURE SINE WAVE
INVERTER
A Major Project Report
Submitted in partial fulfillment of the
requirements for the award of the degree
of
BACHELOR OF TECHNOLOGY
in
ELECTRICAL and ELECTRONICS ENGINEERING
by
MAYAK TRIPATHI
(BT20EEE003)
GAURAV SINGH BISHT
(BT20EEE006)
JAYENDRA
(BT20EEE022)
under the guidance of
Dr. MAHIRAJ SINGH RAWAT
Assistant Professor, Electrical Engineering Department
DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, UTTARAKHAND
SRINAGAR, PAURI (GARHWAL)
UTTARAKHAND – 246174
AUGUST, 2023

2. ii
©NATIONAL INSTITUTE OF TECHNOLOGY, UTTARAKHAND<2023>
ALL RIGHTS RESERVE

3. i
NATIONAL INSTITUTE OF TECHNOLOGY,
UTTARAKHAND
CERTIFICATE
This is to certify that the work which is being presented in this Major Project entitled “DESIGN
AND DEVELOPMENT OF PURE SINE WAVE INVERTER” submitted by Mayank Tripathi
(BT20EEE003), Gaurav Singh Bisht (BT20EEE006) and Jayendra (BT20EEE022) to National
Institute of Technology, Uttarakhand, is a record of bonafide work carried out under my supervision
and I consider it worthy of consideration for the award of Bachelor of Technology in Electrical and
Electronics Engineering.
The matter embodied in the project has not been previously submitted for the award of other degree
or diploma of this or any university/Institute.
Date: 05-08-2023
Dr. Mahiraj Singh Rawat
Supervisor
(Assistant Professor)
Dr. Sourav Bose
HoD, EE

4. ii
NATIONAL INSTITUTE OF TECHNOLOGY,
UTTARAKHAND
CANDIDATE’S DECLARATION
I hereby certify that the work which is being presented in this Major Project entitled “DESIGN AND
DEVELOPMENT OF PURE SINE WAVE INVERTER” in fulfillment of the requirements for
the award of the degree of Bachelor of Technology in Electrical and Electronics Engineering and
submitted in the Department of Electrical Engineering of National Institute of Technology
Uttarakhand is an authentic record of our own work under the supervision of Dr. Mahiraj Singh
Rawat, Assistant Professor, Department of Electrical Engineering, National Institute of Technology,
Uttarakhand.
The matter presented in this thesis has not been submitted by us for the award of any other degree of
this or any other Institution.
Date: 05-08-2023 Mayank Tripathi
(BT20EEE003)
Gaurav Singh Bisht
(BT20EEE006)
Jayendra
(BT20EEE022)
This is to certify that the above statement made by the candidates is correct to the best of my
knowledge.
Date: 05-08-2023
Dr. Mahiraj Singh Rawat
(Assistant Professor)
Supervisor

5. iii
NATIONAL INSTITUTE OF TECHNOLOGY,
UTTARAKHAND
Acknowledgement
Firstly, we would like to express our sincere and deepest gratitude to our major project supervisor
Dr. Mahiraj Singh Rawat for his unwavering support during our project work. We would like to
thank him for the patience and motivation. His valuable suggestions have brought us out of the
toughest times during our project and his guidance has helped us in shaping our project in the current
form. We could not have imagined having a better supervisor and mentor for our project work, for
which we are ever grateful.
We thank the head of the department Dr. Sourav Bose for his timely support which helped in timely
completion of this project work. We are truly grateful to him for the cooperation extended in the need
of the hour. We take this opportunity to especially thank our friends and colleagues, for their constant
support and encouragement in both happy and tough times.
Last but not the least, we thank our family members. We can’t thank them enough for their
unconditional love, patience and the sacrifices they have made to reach us this stage of life.
Mayank Tripathi
(BT20EEE003)
Date:05/08/23 Gaurav Singh Bisht
(BT20EEE006)
Jayendra
(BT20EEE022)

6. iv
Abstract
This report focuses on DC to AC power inverters, which aim to efficiently transform a DC power
source to a high voltage AC source, similar to power that would be available at an electrical wall
outlet. Inverters are used for many applications, as in situations where low voltage DC sources such
as batteries, solar panels or fuel cells not be converted so that devices can run off of AC power. One
example of such a situation would be converting electrical power from a car battery to run a laptop,
TV or cell phone. The method, in which the low voltage DC power is inverted, is completed hear by
the conversion of the high DC source to an AC waveform using pulse width modulation. Hear we
first convert the low voltage DC power to AC, and then use a transformer to boost the voltage to 120
volts. Hear the focus is on designing an inexpensive, versatile and efficient pure sine wave inverter
that gives a 240V, 1kw pure sine wave output.

7. v
Table of Contents
Certificate I
Candidate’s Declaration II
Acknowledgement III
Abstract IV
Table of Contents V
List of Abbreviations VII
List of Figure
List of Table
VIII
IX
1 Introduction 1
1.1 Introduction 2
1.2 Necessity 2
1.3 Objective 2
1.4 Theme 3
2 Literature Survey 4
2.1 Comparison of Commercially Available Inverters 5
2.2 DC to AC Inversion 7
2.2.1 Square wave Inverter 7
2.2.2 Modified Sine wave Inverter 9
2.2.3 Pure sine wave Inverter 10
2.2.4 H-bridge inverter 10
2.3 PWM 11
2.3.1 2-Level-PWM 11
2.3.2 5-Level PWM 13
2.4 Characteristics of Inverter 14
2.4.1 Sine wave Inverter 14
2.4.2 Capacitive loading 15
2.4.3 Frequency stability 15
2.4.5 Effect of operating Temperature 16
2.4.6 Efficiency 16
3 System Description and Hardware Implementation 17
3.1 Block Diagram 17

8. vi
3.2 Circuit Design 18
3.3 Circuit Working 18
3.4 Hardware Implementation 20
3.4.1 Component Selection and Description 20
3.4.2 Hardware Details of the System 21
4 Discussion and Result 33
4.1 Discussion 33
4.2 Result 35
5 Conclusion 37
5.1 Conclusion 37
5.2 Future Scope 37
5.3 References 38
5.4 Appendix 39

9. vii
List of Abbreviation
Ckt. Circuit
AC Alternating Current
DC Direct Current
IC Integrated Circuit
Vtg. Voltage
THD Total Harmonic Distortion
RMS Root mean Square
FET Field effect transistor
PWM Pulse width modulation
LCD Liquid Crystel display

10. viii
List of Figure
1.1 Block diagram of inverter
2.1 Square, Modified Sine, and Sine wave Comparison
2.2 Square Wave
2.3 Modified sine Wave
2.4 2-Level PWM Comparison Signals
2.5 2-Level PWM Output (Unfiltered)
2.6 2-Level PWM Output (Filtered)
2.7 5-Level PWM Output (unfiltered)
2.8 5-Level PWM Output (filtered)
3.1 Block Diagram of Protection System
3.2 Circuit Diagram of Inverter System
3.3 EGS002 Sinusoid Inverter Driver Board Schematic
3.4 EGS0002 Driver Board Pin Definition
3.5 Connection between EGS002 and 12832 LCD
3.6 EGS002 SPWMRC filter circuit with Output waveformofTEST2and TEST3
3.7 EG8010 pin map
3.8 Observed SPWM unipolar modulation sinusoid output and VFB feedbackwave
3.9 EG8010+IR2106S Sinusoid inverter (unipolar modulation)
3.10 EG8010 Temperature detection circuit
3.11 EG8010 Frequency adjust circuit
3.12 IRLB4132 MOSFET Pinout
3.13 TIP31C NPN Transistor Pinout
3.14 IN4007 Diode
4.1 Circuit Implementation
4.2 Fan for cooling
4.3 Undervoltage
4.4 Blinking of Led of egs002
4.5 Input supply of 24 V

11. ix
4.6 Output waveform of the inverter
4.7 Inverter output voltage

12. x
List of Tables
2.1 Comparison of Inverters, Pure Sine vs. Modified Sine of the Same
Capacity
2.2 Pure sine inverters

13. 1
Chapter 1
Introduction
1.1 Preface
This report focuses on DC to AC power inverters, which aim to efficiently transform a DC power
source to a high voltage AC source, similar to power that would be available at an electrical wall
outlet. Inverters are used for many applications, as in situations where low voltage DC sources such
as batteries, solar panels must be converted so that devices can run off of AC power. One example
of such a situation would be converting electrical power from a car battery to run a laptop, TV or cell
phone. The method, in which the low voltage DC power is inverted, is completed in two steps. The
first being the conversion of the low voltage DC power to a high voltage DC source, and the second
step being the conversion of the high DC source to an AC waveform using pulse width modulation.
Another method to complete the desired outcome would be to first convert the low voltage DC power
to AC, and then use a transformer to boost the voltage to 240 volts. This project focused on the first
method described and specifically the transformation of a high voltage DC source into an AC output.
Of the different DC AC inverters on the market today there are essentially two different forms of AC
output generated: modified sine wave, and pure sine wave.
A modified sine wave can be seen as more of a square wave than a sine wave; it passes the high DC
voltage for specified amounts of time so that the average power and RMS voltage are the same as if
it were a sine wave. These types of inverters are much cheaper than pure sine wave inverters and
therefore are attractive alternatives. Pure sine wave inverters, on the other hand, produce a sine wave
output identical to the power coming out of an electrical outlet. These devices are able to run more
sensitive devices that a modified sine wave may cause damage to such as: laser printers, laptop
computers, power tools digital clocks and medical equipment. This form of AC power also reduces
audible noise in devices such as fluorescent lights and runs inductive loads, like motors, faster and
quieter due to the low harmonic distortion.
In this project, our aim was to design a pure sine wave inverter which is the digital versioned circuit
using micro-controller applications.
There are three types of DC/AC inverters available on the market, which are classified by their output
type: square wave, modified-sine wave and pure sine wave. Off-the-shelf inverters are generally

14. 2
either square wave or modified-sine wave. These types of inverters are less expensive to make and
the output, though delivering the same average voltage to a load, is not appropriate to delicate
electronic devices which rely on precise timing. Pure sine wave inverters offer more accuracy and
less unused harmonic energy delivered to a load, but they are more complex in design and more
expensive. Pure sine wave inverters will power devices with more accuracy, less power loss, and less
heat generation. Pure sine wave inversion is accomplished by taking a DC voltage source and
switching it across a load using an H-bridge. If this voltage needs to be boosted from the DC source,
it can be accomplished either before the AC stage by using a DC-DC boost converter, or after the AC
stage by using a boost transformer. The inverted signal itself is composed of a pulse-width-modulated
(PWM) signal which encodes a sine wave. The duty cycle of the output is changed such that the
power transmitted is exactly that of a sine-wave. This output can be used as it is or, alternatively, can
be filtered easily into a pure sine wave. This report documents the design of a true sine wave inverter,
focusing on the inversion of a DC high-voltage source. It therefore assumes the creation of a DC-DC
boost phase.
1.2 Necessity
In Kenya power outage have become more frequent owing to the lack of incentives to invest in
aged national grid, transmission and distribution infrastructures, as well as the fact that energy
from decentralized, “volatile” renewable sources is not well aligned to work on electricity grids.
With an example of April 15th, 2012, fault at the Kenya Power national control center and July
2011 power rationing regime due to East Africa's drought these brings a challenge to power
facilities like medical centers, households and businesses. Frequent power outages are
inconvenient, expensive and difficult to mitigate without very expensive backup power systems.
Some of solution to this problem is an auxiliary AC power generator and solar panels but the cost
of fossil fuels continues to increase rapidly thus it will not be cost effective in the future while solar
power has some aesthetic, economic and technical drawbacks. A more effective and reliable
alternative is battery power back-up system.
1.3 Objective
The Objectives of our project is to design an inverter that can be derived by PV panel and can be
used to operate AC loads while minimizing the conventional inverter cost and complexity using
Microcontroller. Our system’s main properties are –

15. 3
• Generation of a pure sine wave signal from DC source reducing the dependency on the
fossil fuels and limited energy source.
• Reduction of circuits complexity by using microcontroller to generate modulating signals.
1.4 Theme
In this project, we have used Battery instead of PV panel as DC source. This DC source is fed to
the H-Bridge inverter. In the H-Bridge Inverter, we have used 4 MOSFETs switches. This
MOSFETs are used to convert the DC source to AC source. Besides, we have used EGS002 to
drive the MOSFETs. To generate modulating signals, we have implemented micro-controller
where four modulating signals are used to run those MOSFETs switches. Here, unipolar
modulation scheme is used. As the modulation were performed in very high frequency, we have
implemented a LC low pass filter to remove the harmonics at higher frequencies at the inverter
output. To get 220 v AC, we have used step – up transformer.
Fig. 1.1 Block diagram of inverter

16. 4
Chapter 2
Literature Survey
Electrical power transmission is classified into two methods: alternating current and direct current.
Alternating current can be found in AC motor drives and long distance power transmission. The
cyclic nature of alternating current enables the use of transformers, which use magnetic principles
to alter voltage levels. By stepping up an AC voltage, a large amount of power can be transferred
over a long distance with less energy lost in heating up a conductor due to a lower current
requirement, since P=I2 R. As such, AC power is more conventional than high voltage DC systems
due to the ease of stepping up voltage for transmission and stepping voltage down to household
outlet levels.
DC voltage also has a place in powering devices. Wherever there is a changing electrical current,
a changing magnetic field accompanies it. In a device-level electrical circuit, the magnetic
variations introduced by AC current manifest themselves as electrical noise. The effects of this can
range from audible line hum in an audio system to inaccurate measurements in an electronic
instrument. Thus, it is commonplace for a device such as an MP3 player to employ DC voltages
that have been rectified and filtered from an AC wall outlet. An MP3 player also proves one other
benefit of DC power transmission: it can be done with a compact form factor. Without a need for
transformers or switching circuitry, battery-powered MP3 players, or any other portable device,
can be made small enough to fit into a pocket.
DC voltage also has a place in powering devices. Wherever there is a changing electrical current,
a changing magnetic field accompanies it. In a device-level electrical circuit, the magnetic
variations introduced by AC current manifest themselves as electrical noise. The effects of this can
range from audible line hum in an audio system to inaccurate measurements in an electronic
instrument. Thus, it is commonplace for a device such as an MP3 player to employ DC voltages
that have been rectified and filtered from an AC wall outlet. An MP3 player also proves one other
benefit of DC power transmission: it can be done with a compact form factor. Without a need for
transformers or switching circuitry, battery-powered MP3 players, or any other portable device,
can be made small enough to fit into a pocket.

17. 5
Fig. 2.1: Square, Modified Sine, and Sine wave Comparison
A more precise method of DC/AC conversion is the modified sine wave, which introduces a dead
time in a normal square wave output so that higher peak voltages can be used to produce the same
average voltage as a sinusoidal wall-outlet output. This method produces fewer harmonics than
square wave generation, but it still is not quite the same as the AC power that comes from an AC
outlet. The harmonics that are still present in a modified sine wave make modified sine-wave
inverters unsuitable for use while electrical noise is a concern, such as in medical devices which
monitor the vital signs of a human.
Pure sine wave DC/AC conversion will introduce the least amount of harmonics into an electrical
device, but are also the most expensive method. Since the AC sine wave must come from a DC
source, switching must still take place. However, switching takes place with logic so that the
energy delivered to a load approaches that of a pure sine wave. This means that extra components
and design considerations are involved in the control circuitry of a pure sine wave inverter, driving
up cost.
2.1 Comparison of Commercially Available Inverters
Market research revealed some generalizations that can be made about modified-sine and pure sine
wave inverters. A comparison was performed between Duracell (by Xantrex) modified sine wave
inverters and the Samlex PST series of pure sine wave inverter. For a more relevant comparison,
each series of inverters had variants available in 300-watt and 1000-watt ratings. In general, the

18. 6
Samlex inverters have larger dimensions, compared to their modified-sine counterparts, and much
higher cost. This is due to the added circuitry necessary to produce a pure sine wave. Note that all
inverters operate from 12VDC input power. The commonalities that the inverters share hint at
necessary features that any inverter should have. The inclusion of forced-air cooling, input
protection, and overload protection are needed for the safe operation of inverters.
It should be noted that modified-sine wave inverters are not rated for Total Harmonic Distortion
(THD). Rating a modified-sine wave inverter for harmonic distortion would be useless, for their
intended use is not to reduce the harmonics introduced to devices. Their purpose is to provide
affordable and portable AC power. A question of efficiency is brought up in the discussion of
harmonics. The pure sine wave inverters are 5% less efficient, but this rating is from the conversion
of battery energy to modified sine-wave output. This does not take into consideration the effect of
harmonics on battery-to-device output efficiency.
Table 2.1: Comparison of Inverters, Pure Sine vs. Modified Sine of the Same Capacity

19. 7
With the dissection of a commercially available DC/AC modified sine wave inverter, some lessons
were learned about the design of power inverters. An exterior examination prompted thoughts about
cooling, as this particular inverter had a plastic body, but with forced air cooling via an internal fan.
There was also a 5V out USB port, but that is not important to this project which aims only to design
a device capable of DC/AC inversion. The alligator clip battery leads were used since operation from
a 12V car battery was intended. This inverter had two NEMA 5–15 (North American 15 A/125 V
grounded) output plugs.
Table: 2.2 Pure sine inverters
2.2 DC to AC Inversion
2.2.1 Square Wave Inverters
DC to AC conversion is most commonly done through use of MOSFET inverter circuits, which can
switch the voltage across the load, providing a digital approximation of the desired AC signal. The
simplest variant of this inversion is the production of a square wave approximation of a sine wave
(Figure 2.2). For a square wave, the load voltage must be switched merely from high to low, without
the need for an intermediate step (i.e. 0V). In order to deliver the same power as the sine wave to be
approximated, the amplitude of the square wave must be the sine wave's RMS value. This way, the
average voltages, and therefore the power delivered, will be the same for the two waveforms. Square
wave inverters are very rarely used in practice, as many devices which utilize timing circuits that rely
on something close to the sine wave from the power company cannot operate with such a rough
approximation. In addition, a square wave has relatively large 3rd and 5th harmonic components,
which burn power and severely cut down on the efficiency of devices using such inverters as a power
source.
The Square Wave Inverter derives its name from the shape of the output waveform. Square wave
inverters were the original ―electronic‖ inverter. The first versions, such as TrippliteỘ, use a
mechanical vibrator type switch to break up the low voltage DC into pulses. These pulses are then

20. 8
applied to a transformer where they are stepped up. With the advent of semiconductor switches the
mechanical vibrator was replaced with ―solid state‖ transistor switches. A common circuit topology
referred to as ―push-pull‖ is used to produce a square wave output the basic theory of operation
behind a push-pull design is as follows:
The Square Wave Inverter derives its name from the shape of the output waveform. Square wave
inverters were the original ―electronic‖ inverter. The first versions, such as TrippliteỘ, use a
mechanical vibrator type switch to break up the low voltage DC into pulses. These pulses are then
applied to a transformer where they are stepped up. With the advent of semiconductor switches the
mechanical vibrator was replaced with ―solid state‖ transistor switches. A common circuit topology
referred to as ―push-pull‖ is used to produce a square wave output the basic theory of operation
behind a push-pull design is as follows:
The top transistor switch closes and causes current to flow from the battery negative through the
transformer primary to the battery positive; This induces a voltage in the secondary side of the
transformer that is equal to the battery voltage times the turn’s ratio of the transformer. Note: Only
one switch at a time is closed.
Fig. 2.2: Square Wave
After a period of approximately 8ms (one-half of a 60 Hz AC cycle), the switches flip- flop. The top
switch opens and then the bottom switch closes allowing current to flow in the opposite direction.
This cycle continues and higher voltage AC power is the result.
The major problem with the push-pull approach is that the current in the transformer has to suddenly
reverse directions. This would be like shifting your car into reverse at fifty miles per hour. This causes

21. 9
a large reduction in efficiency as well as potential for large transients, thus degrading the waveform.
Another drawback is the transformer required for a push-pull design must have two primaries. This
is a complex task to design a transformer meeting this requirement and increases cost and bulkiness.
Square wave inverters are still produced but have several m drawbacks. The output wave form has
high total harmonic distortion (Ti-ID). It does work okay for powering motors although the motor
will generate excess heat. Most electronic equipment will not operate well (if at all) from a square
wave. This is due to waveform characteristics, and lack of voltage regulation. The peak voltage of
the output pulse is directly related to buffer voltage. Since the transformer ratio is fixed, any change
in battery voltage will affect the peak output voltage. For a square wave, RMS voltage is equal to
peak voltage and as a result power output is dependent on battery voltage. Finally, most square wave
inverters have mediocre efficiency (typically about 80%), and the idle power draw is relatively high.
2.2.2 Modified Sine Wave Inverters
A very common upgrade to the square wave inverter is the modified sine wave inverter. In the
modified sine wave inverter, there are three voltage levels in the output waveform, high, low, and
zero (figure 2.3), with a dead zone between the high and low pulses.
Fig. 2.3: Modified sine Wave
The modified sine wave is a closer approximation of a true sine wave than is a square wave, and can
be used by most household electrical devices. As such, it is extremely common to see this type of
inversion in commercial quality inverters. Despite being much more viable than a simple square

22. 10
wave, the modified sine wave has some serious drawbacks. Like the square wave, modified sine
waves have a large amount of power efficiency loss due to significant harmonic frequencies and
devices that rely on the input power waveform for a clock timer will often not work properly. Despite
the inherent drawbacks, many devices can work while powered by a modified sine source. This
makes it an affordable design option for such implementations as household uninterruptible power
supplies.
2.2.3 Pure Sine Wave Inverters
The best power source for most applications is a pure 50 Hz sine wave, identical to the 120Vrms
source available from any US power company. All low power household plug-in devices are designed
to work with this source (high power devices such as cooking ovens use a 240V source) and, as such,
will be most likely to work properly and most efficiently on such a source. A true sine wave source
is produced most easily for high power applications through rotating electrical machinery such as
naval gas-turbine generators, house-hold diesel or gasoline backup generators, or the various
generators employed by power companies that employ a shaft torque to create an AC current. These
sources provide a relatively clean, pure sine wave (lacking significant harmonics and high frequency
noise) thanks to their analog rotational make-up. Such rotating machinery can be inappropriate for
low-power backup supply usage due to their high cost, large size and required maintenance. As such,
a smaller, digital pure sine wave inverter can be extremely useful.
2.2.4 H-Bridge Inverter
The H-Bridge topology accomplishes its task in much the same manner as a push-pull topology. The
main advantage of this design is the simplicity of needing only one primary winding on tile
transformer. H-Bridge inverters have evolved with improvement in transistor characteristics. Since
current flows through two transistor switches in series, instead of one as in the push-pull design, older
more inefficient transistors meant twice the losses in the inverter. This kept push-pull topologies as
the primary means of producing square and modified square waveforms. The advent of FET‘s (Field
Effect Transistors) allows the H-Bridge design to be easily utilized. The transistors are divided into
four groups or ―corners‖ with the transformer primary connected across the middle of the ―bridge‖
thus forming an ―HI pattern. In practice each transistor switch is made up of multiple transistors in
parallel allowing higher current handling and lower resistance when the switches turn on (called ―on
resistance‖ of the transistor). Notice also that there is no off time shorting winding in the H-Bridge
transformer. The current flow still reverses direction but now the shorting is accomplished by closing
the bottom two switch groups at the same type. This effectively shorts the transformer primary

23. 11
removing residual current flow after the upper set of switches turn off Just as in a push-pull circuit,
the transistors are switched on and off in a specific pattern to produce each part of the waveform. The
pattern is as follows:
Two opposite corners of the bridge are closed, allowing current to flow from the battery negative
through the transformer primary to the positive terminal of the battery (Figure2.7). This current
induces a current flow in the secondary of the transformer, which has a peak voltage equal to the
battery voltage times the turn‘s ratio of the transformer. After a period of time (variable according to
pulse width modulation for voltage regulation) the switches that were closed open, and the bottom
two transistor switches close providing off-time Shorting. The length of the on and off-time is
determined according to the PWM controller. Next the two corners opposite step A, close and allow
current flow through the transformer in a direction opposite to the current flow. After this cycle is
completed, the bottom switches close for off-time shorting and then the cycle repeat in this way AC
is produced. An inverter system consists of: AUTO - CHANGE OVER CIRCUIT: Which has a relay
and converter, which are sequential switches? The relay controls the inverter neutral state and power
Holding company supply, the comparator switches between the battery to the oscillator circuit and
the charging circuit. The relay cut off the charging circuit to the terminal of the battery. OVER -
CHARGING CUT - OFF: This is by the operation of the comparator which compares the battery
voltage with a fixed reference and detect when is fully charged. THE INVERTER STAGE: This
convert DC to AC input, thereby providing reliably stable output voltage and frequency to the load
when the main supply fails. LOW DC VOLTAGE INDICATOR: This sense the operational state of
the battery when drained, hence shuts down after the time lapse of five minutes.
2.3 PWM
2.3.1 2-Level PWM
The most common and popular technique of digital pure-sine wave generation is pulse-width
modulation (PWM). The PWM technique involves generation of a digital waveform, for which the
duty cycle is modulated such that the average voltage of the waveform corresponds to a pure sine
wave. The simplest way of producing the PWM signal is through comparison of a low-power
reference sine wave with a triangle wave (2.4). Using these two signals as input to a comparator, the
output will be a 2- level PWM signal (2.5). This PWM signal can then be used to control switches
connected to a high voltage bus, which will replicate this signal at the appropriate voltage. Put
through an LC filter, this PWM signal will clean up into a close approximation of a sine wave (figure
2.6). Though this technique produces a much cleaner source of AC power than either the square or
modified sine waves, the frequency analysis shows that the primary harmonic is still truncated, and

24. 12
there is a relatively high amount of higher level harmonics in the signal.
Fig. 2.4: 2-Level PWM Comparison Signals
Fig. 2.5: 2-Level PWM Output (Unfiltered)
Fig. 2.6: 2-Level PWM Output (Filtered)

25. 13
2.3.2 5-Level PWM
In order to create a PWM signal which more closely follows the desired sine wave output, the
design described for the 3-level PWM technique can be expanded to 5-, 7- and 9+ level PWM.
Each additional 2 levels added on top of the 3-level design adds an H-bridge (added in series), a
comparator, and a summer. The added accuracy of the signal due to increasing the level therefore
brings with it the addition of components, and the space, cooling, and power they require. Control
signals must be created separately for each H-bridge, each of which correspond to one layer of the
sine voltage (figure 2.7). Higher level PWM also requires multiple isolated voltage buses. For
example, the 5- level PWM circuit requires two isolated buses at 1/2 the voltage of the
corresponding 3-level circuit. The buses must be isolated, as they need to be connected in series.
In the 5-level PWM circuit, one half of each H-bridge is controlled by the square wave from the 3-
level circuit, and simply controls polarity across the bridge.
Fig. 2.7: 5-Level PWM Output (unfiltered)
The other half of each bridge is controlled by the PWM output of each respective comparator. The
resulting PWM signal is shown in figure 2.7, and the filtered sine wave output is shown in figure
21. One of the advantages of higher level PWM generation is that there is less of a voltage swing
from the minimum and maximum of each step, which results in less power loss due to the slope
up and down for each step (known as dv/dt losses). This reduced power loss results in higher
efficiency for the inverter. This increased efficiency must be considered in balance with the
addition of components and frequency effects which must be filtered out. The frequency plot of
the 5-level PWM technique can be seen to be improved over that of the 3- level scheme (figure
2.8). The harmonic frequencies are reduced, as in the 3-level technique, but the magnitude of the

26. 14
primary is significantly larger. Note that these plots show only harmonics of the 60Hz primary,
and thus do not show the effects of the switching frequencies. The improvement of the 5-level
PWM can, however, still be seen in the difference of the primary frequency's magnitude.
Fig. 2.8: 5-Level PWM Output (filtered)
2.4 Characteristics of the inverter
2.4.1 Sine wave inverters
As explained earlier, most DC-AC inverters deliver a modified sine wave Output voltage, because
they convert the incoming DC into AC by using MOSFET transistors as electronic switches. This
gives very high conversion efficiency, but the alternating pulses. Output waveform is also relatively
rich in harmonics. Some appliances are less than happy with such a supply waveform, however.
Examples include light dimmers, variable speed drills, sewing machine speed controls and some laser
printers. Because of this, inverter manufacturers do make a small number of models which are
designed to deliver a pure sine wave output. Generally speaking these inverters use rather more
complex circuitry than the modified sine wave type, because it’s hard to produce a pure sine wave
output while still converting the energy into AC efficiently. As a result, pure sine wave inverters tend
to be significantly more expensive, for the same output power rating. The most common type of pure
sine wave inverter operates by first converting the low voltage DC into high voltage DC, using a high
frequency DC-DC converter. It then uses a high frequency PWM system to convert the high voltage
DC into chopped AC, which is passed through an L-C low pass filter to produce the final clean 50Hz
sine wave output. This is like a high-voltage version of the single-bit digital to analog conversion
process used in many CD players.

27. 15
Another complication of the fairly high harmonic content in the output of modified sine wave
inverters is that appliances and tools with a fairly inductive load impedance can develop fairly high
voltage spikes due to inductive - back EMF - These spikes can be transformed back into the H bridge,
where they have the potential to damage the MOSFETs and their driving circuitry. It’s for this reason
that many inverters have a pair of high-power zener diodes connected across the MOSFETs the
zeners conduct heavily as soon as the voltage rises excessively, protecting the MOSFETs from
damage. Or there are transistors with build in diode to protect from these back voltages.
2.4.2 Capacitive loading
Actually there’s a different kind of problem with many kinds of fluorescent light assembly: not so
much inductive loading, but capacitive loading. Although a standard floury light assembly represents
a very inductive load due to its ballast choke, most are designed to be operated from standard AC
mains power. As a result they are often provided with a shunt capacitor designed to correct their
power factor when they are connected to the mains and driven with a 50Hz sine wave. The problem
is that when these lights are connected to a DC-AC inverter with its Modified sine wave output, rich
in harmonics, the shunt capacitor doesn’t just correct the power factor, but drastically over corrects.
Because its impedance is much lower at the harmonic frequencies. As a result, the floury assembly
draws a heavily capacitive load current, and can easily overload the inverter. In cases where
fluorescent lights must be run from an inverter, and the lights are not going to be run from the mains
again, usually the best solution is to either remove their power factor correction capacitors altogether
or replace them with a much smaller value.
2.4.3 Frequency stability
Although most appliances and tools designed for mains power can tolerate a small variation in supply
frequency, they can malfunction, overheat or even be damaged if the frequency changes significantly.
Examples are electromechanical timers, clocks with small synchronous motors, turntables in older.
And many reel-to-reel tape recorders. To avoid such problems, most DC-AC inverters include
circuitry to ensure that the inverter’s output frequency stays very close to the nominal mains
frequency: 50Hz, or 60Hz. in some inverters this is achieved by using a quartz crystal oscillator and
divider system to generate the master timing for the MOSFET drive pulses. Others simply use a fairly
stable oscillator with R-C timing, fed via a voltage regulator to ensure that the oscillator frequency
doesn’t change even if the battery voltage varies quite widely in our project we programmed IC which
is called PIC to give me SPWM with frequency 50Hz.

28. 16
2.4.5 Effect of Operating Temperature:
The power output of an inverter is dramatically decreased as its internal temperature rises (this is
sometimes called its 5, 10 & 30-minute rating; but in reality if the inverter cannot remove the heat
quick enough, then the power will rapidly drop off). Many of our models are rated at a staggering
40°C, such as Prosine, with a classic comparison between a Pro sine 1000 and a low cost 1500watt
modified as follows. The following chart provides a comparison between the Prosine 1000i rated at
40°C and a common 1500watt inverter rated at 25°C.
2.4.6 Efficiency:
It is not possible to convert power without losing some of it (it's like friction). Power is lost in the
form of heat. Efficiency is the ratio of power out to power in, expressed as a percentage. If the
efficiency is 90 percent, 10 percent of the power is lost in the inverter. The efficiency of an inverter
varies with the load. Typically, it will be highest at about two thirds of the inverter's capacity. This
is called its "peak efficiency." The inverter requires some power just to run itself, so the efficiency
of a large inverter will below when running very small loads in a typical home, there are many hours
of the day when the electrical load is very low. Under these conditions, an inverter's efficiency may
be around 50 percent or less. Because the efficiency varies with load, don't assume that an inverter
with 93 percent peak efficiency is better than one with 85 percent peak efficiency. If the 85 percent
efficient unit is more efficient at low power levels, it may waste less energy through the course of a
typical day.

29. 17
Chapter 3
System Description and Hardware
Implementation
3.1 Block Diagram
Fig. 3.1: Block Diagram of Protection System

30. 18
3.2 Circuit Design
Fig. 3.2: Circuit Diagram of Inverter System
3.3 Circuit Working
DC Power Supply: The inverter system is connected to a DC power supply(24 V), typically a battery
bank. This DC voltage is the input to the inverter and serves as the source for generating the AC
output.
Voltage Regulation: The EGS002 chip monitors the input DC voltage and ensures it remains within
safe operating limits. It may include overvoltage and undervoltage protection to prevent damage to
the inverter components.

31. 19
Microcontroller/Processor: The EGS002 chip contains a microcontroller or microprocessor that
controls the entire operation of the inverter. This microcontroller generates the necessary control
signals for generating the pure sine wave output.
PWM Generation: The microcontroller generates high-frequency PWM signals based on the desired
AC output frequency. For instance, for a 60Hz AC output, it might generate PWM signals at a
frequency of several kHz. The duty cycle of these PWM signals determines the output voltage level.
Reference Sine Wave Generation: The microcontroller generates a reference sine wave signal, which
is a low-frequency sine wave (50Hz or 60Hz) that represents the desired AC output waveform.
Comparison: The reference sine wave is compared to the high-frequency PWM signal. The
microcontroller adjusts the duty cycle of the PWM signal to match the instantaneous amplitude of
the reference sine wave. This comparison process generates a modulated PWM signal.
Filtering the PWM Signal: The modulated PWM signal is then passed through a filter network. This
network consists of inductors and capacitors that act as a low-pass filter. It filters out the high-
frequency components of the PWM signal, leaving behind a waveform that closely resembles a
sinusoidal waveform.
Driver Stage: The filtered signal is then amplified by a driver stage. This stage uses transistors to
amplify the PWM signal to levels suitable for driving the power stage.
Power Stage: The power stage is responsible for switching the DC input voltage to create an AC
output waveform. It typically consists of a bridge configuration of power transistors or MOSFETs.
These transistors switch on and off rapidly according to the amplified PWM signal.
Output Filter: The switching of the power transistors generates a stepped waveform that still contains
some high-frequency harmonics. This waveform is passed through another filter network, similar to
the earlier filter, which further smooths out the waveform and removes remaining high-frequency
components.
Transformer : A transformer is used to provide isolation between the inverter and the load, and also
to adjust the output voltage level.

32. 20
AC Output: The final output of the inverter is a pure sine wave AC voltage that closely resembles
the utility power. This output can be used to power a wide range of AC devices, providing a clean
and stable power source.
It's important to note that the EGS002 chip simplifies many of these processes by integrating the
PWM generation, control logic, and protection features. The detailed implementation of the circuit,
choice of components, and additional features such as protection mechanisms can vary based on the
specific application and design requirements.
3.4 Hardware Implementation
It involves the details of the set of design specifications. The hardware design consists of, the
selection of system components as per the requirement, the details of subsystems that are required
for the complete implementation of the system has been carried out. It involves the component
selection, component description and hardware details of the system designed. 1. Component
selection and description. 2. Hardware details of the system designed.
3.4.1 Component Selection and Description
Inverter Design includes the following components:-
- EGS002 SPWM Inverter Driver Module
- IRF3205 or IRLB4132 MOSFETS (16x)
- 12V to 220V (500W/1000W) Transformer
- TO-220 Isolation Set (16x)
- TIP31C NPN Transistor
- 7805 Regulator
- 1N4007 Diode (8x)
- 10k Ohm NTC Thermistor
- 10k Ohm Multi-turn Trimmer
- 10 Ohm Resistor (4x)
- 2.2k Ohm Resistor

33. 21
- 10k Ohm Resistor (4x)
- 100k Ohm Resistor (2x)
- 470nF 25v Capacitor
- 2.2uF +350v Capacitor
- 2.2uF 25v Capacitor
- 10uF 25v Capacitor
- 100uF 25v Capacitor
3.4.2 Hardware Details of the System
1. EGS002
(i) Description:
EGS002 is a driver board specific for single phase sinusoid inverter. It uses ASIC EG8010 as control
chip and IR2110S as driver chip. The driver board integrates functions of voltage, current and
temperature protection, LED warning indication and fan control. Jumper configures 50/60Hz AC
output, soft start mode and dead time. EGS002 is an improved version of EGS001 that is compatible
of EGS001’s original interfaces.
Fig. 3.1: EGS002 Sinusoid Inverter Driver Board Schematic
EGS002 also integrates cross-conduction prevention logic to enhance its ability of anti-interference,

34. 22
and LCD display interface for users’ convenience to use chip’s built-in display function. EG8010 is
a digital pure sine wave inverter ASIC (Application Specific Integrated Circuit) with complete
function of built-in dead time control.
It applies to DC-DC-AC two stage power converter system or DC-AC single stage low power
frequency transformer system for boosting. EG8010 can achieve 50/60Hz pure sine wave with high
accuracy, low harmonic and distortion by external 12MHz crystal oscillator. EG8010 is a CMOS IC
that integrates SPWM sinusoid generator, dead time control circuit, range divider，soft start circuit,
circuit protection, RS232 serial communication, 12832 serial LCD unit, and etc.
1. EGS002 Front View:
Fig. 3.2 EGS0002 Driver Board Pin Definition
(ii) Pin Description
Designator Name I/O Descriptions
1 IFB I
AC Output Current Feedback. Overcurrent protection turns on when pin’s input
voltage is over 0.5V
2 GND GND Ground
3 1LO O Right bridge low side gate drive output
4 GND GND Ground
5 VS1 O Right bridge high side floating supply return
6 1HO O Right bridge high side gate drive output
7 GND GND Ground
8 2LO O Left bridge low side gate drive output

35. 23
9 VS2 O Left bridge high side flating supply return
10 2HO O Left bridge high side gate drive output
11 GND GND Ground
12 +12V +12V +12V voltage input. (range: 10V-15V)
13 GND GND Ground
14 +5V +5V +5V power supply
15 VFB I
AC Output voltage feedback. Referring to EG8010 datasheet for specific function and
circuit.
16 TFB I
Temperature feedback. Overtemperature protection turns on when pin’s input voltage
is over 4.3V
17 FANCTR O
Connect to the fan control. When detects a temperature over 45℃, FANCTR
outputs high level “1” to turn on the fan. When the temperature is lower than 40℃,
FANCTR outputs low level “0” to turn off the fan.
* The
followings are
LCD display
interface
*1 +5V +5V
+5V power supply for the LCD
*2 GND GND
Ground
*3 LCDDI I/O
LCD Serial Data
*4 LCDCLK O
LCD Serial Clock
*5 LCDEN O
LCD Chip Select
*6 LED+ +5V
+5V power supply for the backlight
*7 LED- GND
Ground
(iii) Jumper settings
Designator Name Mark Setting Description
1 FS0
JP1 When JP1 is short, it selects AC output frequency at 60Hz
JP5 When JP5 is short, it selects AC output frequency at 50Hz
2 SST
JP2 When JP2 is short, it enables 3 seconds soft start mode
JP6 When JP6 is short, it disables soft start mode
3 DT0
JP3 When JP7 and JP8 are short, dead time is 300ns.
When JP3 and JP8 are short, dead time is 500ns.
When JP4 and JP7 are short, dead time is 1.0us.
When JP3 and JP4 are short, dead time is 1.5us.
JP7
4 DT1
JP4
JP8
*5 LED+ JP9
When JP9 is short, LCD backlight is on
When JP9 is open, LCD backlight is off
(iv) Led Warning Indication

36. 24
EGS002 driver board provides LED warning indication function. User can determine problem
according to the followings:
• Normal：Lighting always on
• Overcurrent：Blink twice, off for 2 seconds, and keep cycling
• Overvoltage：Blink 3 times, off for 2 seconds, and keep cycling
• Undervoltage：Blink 4 times, off for 2 seconds, and keep cycling
• Overtemperature：Blink 5 times, off for 2 seconds, and keep cycling
(v) LCD Display Interface
EGS002 integrates LCD display interface for users’ convenience to test chip’s built-in display
function that EG8010 supports. Shielding cable is required for connecting EGS002 driver board and
LCD, otherwise inverter’s high voltage and high current environment will significantly interfere
driver board’s operation.
EG8010 supports 12832 LCD (default) orLCD3220 that we specifically designed. Because two
LCDs’ drivers are different, user has to specify if intends to buy LCD3220. Salesperson will ship
12832 LCD as default if not otherwise specified.
(vi) LCD Connection diagram
Fig. 3.3. Connection between EGS002 and 12832 LCD
(vii) EGS002 Driver Board Testing
1. Connect IFB, VS1, VS2, VFB and TFB to the ground during testing.
2. Connect DC 5V to pin +5V and DC 12V (voltage can be between 12V and 15V) to pin+12V
3. Connect oscilloscope to TEST1 to TEST4 to observe waveforms. TEST1 and TEST2
outputs fundamental frequency square wave, which is shown as CH1 blue waveform in figure

37. 25
5-3.TEST3 and TEST4 outputs unipolar modulation wave. When TEST3 and TEST4 are
connected to RC filter, it will output waveform shown as CH2 red waveform in figure 5-3.
4. Because pin VFB is grounded, undervoltage protection is going to turn on in 3 seconds.
Test1~Test 4 will all shut down; LED blinks four times, off for 2 seconds and keep cycling.
5. When EGS002 is connected to the power supply again, user can observe waveforms for
another 3 seconds.
Fig.3.4: EGS002 SPWMRC filter circuit with Outputwaveformof TEST 2and TEST3
2. EG8010
(i) Description
EG8010 is a digital pure sine wave inverter ASIC (Application Specific Integrated Circuit) with
complete function of built-in dead time control. It applies to DC-DC-AC two stage power converter
system or DC-AC single stage low power frequency transformer system for boosting. EG8010 can
achieve 50/60Hz pure sine wave with high accuracy, low harmonic and distortion by external 12MHz
crystal oscillator. EG8010 is a CMOS IC that integrates SPWM sinusoid generator, dead time
control circuit, range divider soft start circuit, circuit protection, RS232 serial communication,12832
serial LCD unit, and etc.
(ii) DATASHEET
1. 5V single supply
2. 4 settings of output frequency can set by 2 pins
• 50Hz constant frequency sine-wave
• 60Hz constant frequency sine-wave
或
接示波器

38. 26
• 0-100Hzadjustable frequency sine-wave
• 0-400Hz adjustable frequency sine-wave
3. 2 modulation modes can set by1 pin
• Unipolar modulation
• Bipolar modulation
4. 4 settings of dead time can set by 2 pins
• 300nS
• 500nS
• 1.0uS
• 1.5uS
5. External 12MHz crystal oscillator
6. 23.4KHz Modulation frequency
7. Output Voltage Current Temperature detect and handle
8. 3 seconds soft start can select by 1 pin
9. USART communication support
10. Voltage Current Temperature Frequency Display support by external LCD
11. Parameters and functions customize support
Application
• Single-Phase sinusoid inverter
• Solar power generation inverter
• Wind power generation inverter
• UPS(Uninterruptible powersupply)
• Digital Generator
• Medium frequency power supply
• Single-phase motor speed controller
• Single-phase frequency transformer

39. 27
(iii) Pinout:-
Fig. 3.5 EG8010 pin map
(iv) Application Note :
EG8010 works under two modulation modes: unipolar modulation and bipolar modulation.
Under unipolar modulation, only one bridge (EG8010 pins SPWMOUT3 & SPWMOUT4) is
used for SPWM modulate output, and another bridge (EG8010 pins SPWMOUT1，
SPWMOUT2) is used for fundamental wave output. A filter inductor needs to connect to
SPWM output port, and a voltage feedback circuit needs to connect to SPWM inductor’s
output port. Under bipolar modulation, both bridges (EG8010 pins SPWM3, SPWM4,
SPWM1, SPWM2) are used for SPWM output. Using both inductors will result in better
flirting, a voltage feedback circuit need difference and feedback handling by voltage divider
of both channels.
Under unipolar modulation, EG8010’s voltage feedback process is through measuring the AC
voltage output of inverter by pin(13)VFB. Pin (16)FRQADJ/VFB2 only functions as
FRQADJ, while VFB2 feedback has no effect. For such voltage sampling and feedback circuit,
it calculates the error between measured peak voltage and the sinusoid voltage reference (3V),

40. 28
and adjusts the output voltage accordingly. When output voltage increases, the pin voltage
increases. The circuit does the error calculation and adjust range divider factor, therefore
decreases the voltage to achieve voltage stabilization. Conversely, as the voltage on this pin
decreases, the chip will increase output voltage.
Figure 3.6: Observed SPWM unipolar modulation sinusoid output and VFB feedbackwave
Fig.3.7: EG8010+IR2106S Sinusoid inverter (unipolar modulation)
Figure 3.6 is the actual testing wave under unipolar modulation. EG8010 uses the peak point
sampling to output voltage, which has advantages of accurate voltage stabilization and short
voltage adjustment time. If output voltage is deviated by some reasons such as change of load or

41. 29
input voltage, EG8010 can recover to expected output voltage in one to three AC cycle.
(v) Temperature Feedback
Pin TFB measures inverter’s environment temperature. Its main functions are overtemperature
protection detection and displaying the environment temperature onto 12832 LCD. For
temperature detection circuit shown in figure 3.7, NTC thermal resistor RT1 and measuring
resistor RF1 form a simple voltage divider circuit. Voltage changes as the NTC resistance
changes, and thus we can acquire the corresponding temperature. Thermal resistor has 10k
resistance at 25℃(B=3380). Pin TFB’s overtemperature voltage sets at 4.3V. EG8010 will set
the level of SPWMOUT1 to SPWMOUT4 at “0” or “1” and shut down all power MOSFET
to decrease the voltage to zero depending on pin (9)PWMTYP’s setting. Once overtemperature
protection activates, EG8010 will re-determine environment temperature. If pin TFB ‘s voltage
is below 4.0V, EG8010 will turn off overtemperature protection and the inverter functions
regularly. If overtemperature protection is not used, this pin needs to be grounded.
Fig. 3.7: EG8010 Temperature detection circuit
(vi) Frequency Setting
EG8010 has two frequency modes: constant frequency mode and adjustable frequency mode. In
adjustable frequency mode, EG8010 only uses unipolar modulation, and pin (20)MODSEL has
to connect to low level. Pins FRQSEL1 and FRQSEL0 set the frequency mode. In constant
frequency mode, “00” outputs 50Hz frequency and “01” outputs 60Hz frequency. FRQADJ has
no function in constant mode. Pin (16) is used as VFB2 voltage feedback circuit under bipolar
modulation. In adjustable frequency mode, “10” outputs frequency in range of 0-100Hz and “11”
outputs frequency in range of 0-400Hz. Pin FRQADJ adjusts the frequency as shown in figure

42. 30
3.8. Pin FRQADJ’s voltage varies from 0-5V, which is corresponding to the fundamental wave
output frequency from 0-100Hz or 0-400Hz. This function accompanies with pin VVVF can be
used in the single phase frequency transformer system.
Fig. 3.8 EG8010 Frequency adjust circuit
3. IRLB4132 MOSFETS
IRLB4132 is a semiconductor POWER MOSFET device mainly used for high-speed switching
applications.
(i) specification
• IRLB4132 is an N-channel silicon POWER MOSFET transistor device
• Drain to source voltage (VDS) is 30V
• Gate to source voltage (VGS) is +/- 20V
• Gate to the threshold voltage (VGS (th)) is 35V, 1.8V & 2.35V
• Drain current (ID) is 150A
• Pulsed drain current (IDM) is 620A
• Power dissipation (PD) is 140W
• Total gate charge (Qg) is 36 to 54nC
• Rise time (tr) is 92ns
• Thermal resistance junction to case (Rth j-C) is 11℃/W
• Junction temperature/ storage temperature range (TJ/Tstg) is between -55 to 175℃
• Body diode reverse recovery (trr) 29 to 44ns
• Input capacitance is 5110pF
• Output capacitance is 960pF
• Very low on-state resistance
• Ultra-low gate impedance

43. 31
• Fully characterized avalanche voltage and current
Fig. 3.9 IRLB4132 MOSFET Pinout
4. TIP31C NPN Transistor
The TIP31C is a base island technology NPN power transistor in TO-220 plastic package with
better performances than the industry standard TIP31C that make this device suitable for audio,
power linear and switching applications. The PNP type is TIP32C.
Fig.3.9: TIP31C NPN Transistor Pinout
5. 1N4007 Diode
Feature:-
• Low forward voltage
• High Surge Current Capability

44. 32
Fig.3.10: IN4007 Diode

45. 33
Chapter 4
Discussion and Result
4.1 Discussion
Fig. 4.1: Circuit Implementation
The above picture shows implemented pure sine wave inverter. The system is fitted in box with an
automatic fan which will run automatically when there is a heating in the system.
Fig. 4.2: Fan for cooling

46. 34
Voltage less then 24 V is considered undervoltage for this scheme. As we can see in Fig 4.1 when
we are giving the input of 20.9 V the led of egs002 module will
Fig. 4.2 Undervoltage
blink repeatedly to indicate undervoltage and the circuit will not work for this.
Fig. 4.3: Blinking of Led of EGS002

47. 35
4.2 Results
The design of the inverter for input voltage of 24V for which it will give an output voltage of 220
V.
Fig. 4.3 Input supply of 24 V
Fig. 4.4 Output waveform of the inverter

48. 36
Fig. 4.5 Inverter output voltage

49. 37
Chapter 5
Conclusions
5.1 Conclusion
The main aim of our project work we have achieved that is converting the DC voltages into
AC voltage. We were successful to have output of 40watt at the frequency of 60 Hz. By using
this, we derived a CFL bulb of 11 watt and a fan of 28 watt. By achieving this success, we are
quite confident to apply this experience for our daily appliances through using the input as
Photovoltaic source at cheap cost.
5.2 Future Scope
This System can be modified to work with larger(1kw) power rating which a larger rated
transformer. Also we can couple this with a solar panel and battery for constant power output.

50. 38
References
[1] A Qazalbash, A Amin, A Manan, M Khalid, "design and implementation of microcontroller
based PWM technique for sine wave inverter" International Conference on power Engineering
Energy and Electrical Drives, , P 163-167, March 2009, IEEE.
[2] Hassaine, E Olías, M Haddadi, A Malek, " Asymmetric SPWM used in inverter grid
connected" Revue des Energies Renouvelables Vol. 10, pp. 421-429, 2007.
[3] Mamun A, M Elahi, M Quamruzzaman , M Tomal, "Design and Implementation of Single Phase
Inverter" International Journal of Science and research IIJSR), Vol.2, P 163-167, February 2013.
[4] M.N Isa, M.I Ahmad, A.Z Murad, M.K Arshad, "FPGA Based SPWM Bridge Inverter ",
American Journal of Applied Sciences, Vol. 4, pp. 584-586, 2007.
[5] B Ismil, S Taib, A Saad, M Isa, " development of control circuit for single phase inverter
using atmel microcontroller" First International Conference PEC, p 437-440, November
2006,IEEE.
[6] S.M Islam, G.M sharif, "microcontroller based sinusoidal PWM inverter for photovoltaic
application" First International Conference development in renewable energy technology, p
1-4, December 2009, IEEE.
[7] P Bhangale, P Sonare, S Suralkar, "design and implementation of carrier based sinusoidal
PWM inverter" International Journal of advanced research in electrical, electronics and
instrumentation engineering, Vol 1, pp. 230-236, October 2012.
[8] R Senthilkumar, M Singaaravelu, " design of single phase inverter using dsPIC30F4013"
International Journal Engineering Research & Technology (IJERT), Vol 2, pp. 6500-6506,
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[9] B Ismail, S Taib, M Isa, I Daut, A.M saad, F Fauzy, "Microcontroller Implementation of single
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Mechatronics Engineering, p 104-107, May 2007.

51. 39
Appendix
Fig. EG8010 block diagram
EG8010 Pin description:
Designator Name I/O Descriptions
26 VCC VCC Power supply
3,12 GND GND Ground
1 DT1 I
DT1, DT0: Dead time setup
“00”: 300ns “10”: 1us
“01”: 500ns“11”: 1.5us
2 DT0 I
4 RXD I USART data receiver
5 TXD O USART data transmitter
6 SPWMEN I SPWM output enable:“0”:Disable “1”:Enable
7 FANCTR O
Extern Fan control:
It turns high to drive the extern fan when the temperature is over than
45℃.It turns low when the temperature is below 40℃.
8 LEDOUT O
LED warning display: Normal:
Over current：
Over voltage： Below voltage：
Over temperature：
9 PWMTYP I
PWM type select
“0”: positive polarity PWM type MOSFET on when SPWMOUT is high
“1” positive polarity PWM type MOSFET on when SPWMOUT is low
Best configuring pin according to driver device and referring to the typical
application schematic below, otherwise will result in both sides of MOS

52. 40
tubes conducting at the same time.
10 OSC1 I 12MHz extern crystal oscillator input
11 OSC2 I 12MHz extern crystal oscillator output
13 VFB I AC output voltage feedback input
14 IFB I AC output current feedback input
15 TFB I Temperature feedback input