DEPARTMENT OF ELECTRONIC ENGINEERING
UNIVERSITY OF ENGINEERING AND TECHNOLOGY
ABBOTTABAD
Project Proposal
Title: DESIGN OF PURE SINE WAVE
INVERTER
Group Members
Name of Student Registration Numbers
MUHAMMAD YOUSAF 17ABELT0766
UMER FAROOQ 17ABELT0786
Supervisor
Supervisor Name: MA’AM QUARAT UL AIN
Supervisor Designation: Lecturer
October 2020
Table of Contents
1. Motivation & Objectives...................................................................................................... 3
2. Methodology ........................................................................................................................ 3
2.1 Theoretical Studies ...................................................................... Error! Bookmark not defined.
2.2 Experimental Setup ..................................................................... Error! Bookmark not defined.
2.3 Method of Analysis ..................................................................... Error! Bookmark not defined.
2.4 Expected Results ......................................................................... Error! Bookmark not defined.
3. Proposed Time Schedule...................................................................................................... 6
4. Budget Description .............................................................................................................. 7
5. References ............................................................................................................................ 7
Undertaking.................................................................................................................................... 8
2
Motivation & Objectives:
In this modern society, electricity has great control over the most daily activities for instance
in domestic and industrial utilization of electric power for operations. Electricity can be
generated from public supply to consumers in different ways including the use of water,
wind, or steam energy to drive the turbine as well as more recently the use of gas.
Generators, solar energy, and nuclear energy are also source of electricity.
In Pakistan, there is inconsistence supply of electricity by the power supplying company to the
consumers. Hence the use of additional electric power source such as electric power generators
and most recently the use of semiconductor power devices such as the Bipolar Transistor,
Thyristors and particularly MOSFET to generate electric power in conjunction with a DC battery
in few kilowatts. An Inverter offers a better additional power source to Generators as well as UPS
considering its long duration, cost effectiveness and maintainability.
Our objective is to design higher levels if multilevel inverter (MLI). MLI which can be designed
by using lower number of semiconductor switches. In conventional MLI higher number of
semiconductor switches or Transistors are required to produce higher levels in the output voltage.
The purpose of the project is to reduces the number of semiconductor switches gate drives, DC
Voltage sources, higher levels of the output and with lower total harmonic distortion (THD) in the
output waveform. Advantages will be low caste, smaller size and lower loss.
Methodology:
Inverter:
An inverter is used to provide uninterrupted 220V AC supply to the load connected to its output
socket. It provides constant AC supply at its output socket, even when the AC mains supply is
not available.
It is a combination of inverter circuit, charger circuit and a battery. The charger circuit keeps
the battery charged when the mains supply is available and when the mains AC fails, the
inverter circuit takes the DC power stored in the battery and converts it into 220V/50Hz AC
supply, which can be used to power any common electronic equipment or computer
systems. It performs the reverse role of rectifier where the AC power is converted into DC
power and functions by chopping DC voltage through various means.
Most of the electrical equipment work with the 220V AC supply but internally, their circuit
work on the DC supply. Hence the external AC supply is converted into DC supply by the
power supply unit on these equipment’s. Any device that works on DC supply can be used
during the mains power breakdown by connecting them to batteries. But batteries have a
fixed life and running power consuming equipment using the battery could be very
expensive. Hence, rechargeable batteries can be used in this type of situation to reduce the
cost. An inverter is used to power device that does not have the facility to connect to a DC
power source or device that requires AC power source for its operation.
The use of semiconductor power devices such as bipolar transistors, thyristors for voltage
amplification, particularly the MOSFET as the power switches, makes the inverter a better
additional power supply. The inverter is less noisy, provides complete automatic switchover
function, possess no environmental threats, less bulky and less expensive to maintain. There
are also other topologies for inverters.
3
Multilevel Inverter:
A multilevel inverter is a power electronic system that synthesizes a sinusoidal voltage
output from several DC sources. These DC sources can be fuel cells, solar cells, ultra-
capacitors, etc. The main idea of multilevel inverters is to have a better sinusoidal voltage
and current in the output by using switches in series. Since many switches are put in series
the switching angles are important in the multilevel inverters because all of the switches
should be switched in such a way that the output voltage and current have low harmonic
distortion. Multilevel inverters have three types. Diode clamped multilevel inverters, flying
capacitor multilevel inverters and cascaded H-bridge multilevel inverter.
The THD will be decreased by increasing the number of levels. It is obvious that an output
voltage with low THD is desirable, but increasing the number of levels needs more
hardware, also the control will be more complicated. It is a tradeoff between price, weight,
complexity, and a very good output voltage with lower THD.
Multilevel Inverter:
Three types of multilevel inverter have been investigated in this thesis.
1. Diode Clamped multilevel inverters
2. Flying Capacitor multilevel inverters
3. Cascaded H-bridge multilevel inverters
Diode Clamped multilevel inverter:
The main concept of this inverter is to use diodes to limit the power devices voltage
stress. The voltage over each capacitor and each switch is Vdc. An n level inverter
needs (n-1) voltage sources, 2(n-1) switching devices and (n-1) (n-2) diodes.
Flying capacitor multilevel inverters
This inverter uses capacitors to limit the voltage of the power devices. The
configuration of the flying capacitor multilevel inverter is like a diode clamped
multilevel inverter except that capacitors are used to divide the input DC voltage. The
voltage over each capacitor and each switch is Vdc.
Cascaded H-bridge multilevel inverter
The concept of this inverter is based on connecting H-bridge inverters in series to get
a sinusoidal voltage output. The output voltage is the sum of the voltage that is
generated by each cell. The number of output voltage levels are 2n+1, where n is the
number of cells. The switching angles can be chosen in such a way that the total
harmonic distortion is minimized. One of the advantages of this type of multilevel
inverter is that it needs a smaller number of components comparative to the Diode
clamped or the flying capacitor, so the price and the weight of the inverter is less than
that of the two former types. Fig.1 shows an n level cascaded H-bridge multilevel
inverter. The switching angles calculation method that is used in this inverter is the
same as for the previous multilevel inverters.
An n level cascaded H-bridge multilevel inverter needs 2(n-1) switching devices
where n is the number of the output voltage level.
4
Pure Sinewave Inverter:
Our Proposed project is to design pure sinewave inverter with output power rating 1KW
using Pulse Width Modulation technique (PWM). The PIC16F628A microcontroller will be
used to generate PWM signal for operating MOSFETs which will result in generating square or
modified sine wave at the output after passing through the LCL filter to remove noises and get
pure sine wave at the output.
Components Used:
1. MOSFET (IRF1010N):
The MOSFET are generally prefer because fast switching devices they are consider as the best
switching devices. IRF is high power mosfets and high switching devices. We will be IRF1010 N
channel mosfets for our inverter to make sinewave.
Fig: 1.1 IRF1010N
A key advantage of a MOSFET is that it requires almost no input current to control the load
current, when compared with bipolar junction transistors (BJTs). In an enhancement
mode MOSFET, voltage applied to the gate terminal can increase the conductivity from the
"normally off" state. In a depletion mode MOSFET, voltage applied at the gate can reduce the
conductivity from the "normally on" state. MOSFETs are also capable of high scalability, with
increasing miniaturization, and can be easily scaled down to smaller dimensions. They also have
faster switching speed (ideal for digital signals), much smaller size, consume significantly less
power, and allow much higher density (ideal for large-scale integration), compared to BJTs.
MOSFETs are also cheaper and have relatively simple processing steps, resulting in
high manufacturing yield.
2. MICRO CONTROLLER (PIC16F628A)
PIC microcontrollers (Programmable Interface Controllers) are electronic circuits that can
be programmed to carry out a vast range of tasks. They can be programmed to be timers or to
control a production line and much more. They are found in most electronic devices such as alarm
systems, computer control systems, phones, in fact almost any electronic device. Many types of
PIC microcontrollers exist, although the best are probably found in the GENIE range of
programmable microcontrollers. These are programmed and simulated by Circuit Wizard
5
software.
PIC Microcontrollers are relatively cheap and can be bought as pre-built circuits or as kits that
can be assembled by the user.
You will need a computer to run software, such as Circuit Wizard, allowing you to program a
PIC microcontroller circuit. A fairly cheap, low specification computer should run the software
with ease. The computer will need a serial port or a USB port. This is used to connect the
computer to the microcontroller circuit.
3. Filter (LCL Filter):
LCL filters must be selected according to the current absorbed by the converter. In case of
converters with very low power rating, a unique LCL filter may be used to supply several
converters, but only in case all start and stop at the same time. If several converters starting
and stopping separately are supplied by the same LCL filter, the system is not effective on
filtering the harmonics. In such case an individual LCL should be used for each converter.
1. Proposed Time Schedule
Sample is given below.
Jan Feb Apr May Jun
Activity Mar
Collection of Literature
Study of Literature
Analysis of Proposed
Scheme
Preparation of Schemes /
Model
Implementation of
Schemes/Model
Analysis & Simulation
Result Formulation
Final Write-up & Thesis
Submission
6
2. Budget Description
Products Name Product Price
MOSFET IRF1010N $2 or Rs.350
Micro Controller PIC16F628A $15 or Rs.2400
LCL Filter $6 or Rs.950
3. References
Write down references used for the proposal here. Use the IEEE referencing style.
I. A. Harbi, Haitham Z. Azazi, Azza E. Lashine & Awad E. Elsabbe (2018). A higher levels
multilevel inverter with reduced number of switches. International Journal of Electronics.
7
Undertaking
I certify that the project work titled “enter title of your research proposal here” is my own work.
The work has not, in whole or in part, been presented elsewhere for assessment. Where material
has been used from other sources it has been properly acknowledged/referred.
Muhammad Yousaf
Reg#17ABELT0766
Umer Farooq
Reg#17ABELT0786
4. Supervisor’s Comments
Take recommendation of your supervisor for your proposed research work here.
Signature of Supervisor
MA’AM QUARAT UL AIN
Supervisor Designation:
Lecturer
