2017
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Item Study of PV System(Department of Electrical and Electronic Engineering, Islamic University of Technology, Board Bazar, Gazipur, Bangladesh, 2017-11-15) Adam, Abdimajid; Joya, JamshidItem New efficient AC-DC converters and their applications(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Saifullah, Khalid; Hysam, Md. Abdullah Al; Haque, Md. Zihad Ul; Asif, SakifAC-DC converters are mostly used as power supplies for microelectronic systems, battery chargers, wind energy applications, electric appliances in household and dc motor drives. Switched-capacitor (SC) network based converters can be good solution to the challenges of 21st century having high voltage conversion ratio and low EMI emissions. The application of this type of converters is in microprocessor based systems where the line voltage requires a steep step down to 3V or even less in order to drive integrated circuits (ICs). In this paper, a new high step down bridgeless single switch AC-DC converter with switched capacitor is proposed. The absence of transformer as well as bridge rectifier reduce the components count, size and cost of the converter. Unlike the existing converters, this proposed buck boost converter is able to achieve simple control structure with single switch, high efficiency, low total harmonic distortion (THD) and high input power factor. Power supplies for microelectronic systems, battery chargers, wind energy applications, electric appliances in the household and dc motor drives require AC-DC converters. The proposed bridgeless Cuk PFC converter in this paper is featured with common ground, transformerless structure, and clear energy delivery process. The absence of bridge rectifiers, transformer and the presence of only two semiconductor switches in the current flowing path during each switching cycle result in less conduction losses and improved thermal management, reducing components count, size and cost of the converter compared to the conventional SEPIC and Cuk PFC converters. Moreover, the presence of two power switches for different half cycles leads to less stress on the power switch. Unlike the existing converters, this proposed bridgeless Cuk PFC converter is able to achieve simple control structure with high efficiency, low total harmonic distortion (THD) and high input power factor. This letter describes a new application of single-ended primary converter (SEPIC) and Cuk converter for dc bipolar net-work. A dc–dc converter configuration based on a combination of both converters is proposed. In the resulting topology, the switching node is shared by the SEPIC and Cuk converter since they have the same instantaneous duty cycle. The main advantage of this topology is that synchronization of various switches is not required, and control terminal is connected to ground which simplifies the design of the gate drive. On the other hand, this configuration allows the connection of renewable energy sources to microgrids (MG)-type bipolar dc link and to cover the current needs of new distributed generation units with efficient, economical, and easy way. To verify its performance, a prototype was designed. Experimental results show as this combination of two converter topologies with appropriated modulation schemes are adequate to use in dc MG.Item Comparison of transmission characteristics of add-drop ring resonators with different geometric shapes(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Badhon, Rashadul Hasan; Kabir, Md. Faiyaz; Rijhum, Ann Noor Bhuiyan; Khan, Md. Zahirul IslamPlasmonic devices have become a very popular topic of research in recent years due to their properties which allow them to outperform conventional electronic devices in many aspects, the most of important of which is their ability to overcome the diffraction limit. This allows Plasmonic devices to be miniaturized to the nanometer scale, which makes them extremely useful for various optical applications. Here, a special class of Plasmonic devices called add-drop ring resonators were investigated. Various configurations of these resonators with different geometric shapes for the ring were proposed. The transmission characteristics of these structures were analyzed and compared by carrying out simulations to calculate the transmission efficiency at the drop and through ports for different wavelengths of light. The effect on the transmission characteristics due to modifications in the structures were also observed. The add-drop ring resonator configurations with elliptical shaped ring and round-edge square shaped ring both performed better than the conventional circular ring design, exhibiting higher transmission efficiencies at the drop port.Item Attendance System using arduino(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Moubarak, Nchouwat N.I.; Lawane, Abdoul Kadiri; Adamou, Nadoukou Idriss; Saidou, AbdourahimouDue to the rapid growing number of students in the ISLAMIC UNIVERSITY OF TECHNOLOGY (IUT) we as electrical and electronics engineering student thought it better to design a student attendance based system that could effectively manage the attendance of students . Attendance is marked after the student have enrolled. For student enrollment, an optical fingerprint sensor is used. Once the fingerprints are taken the name and the student ID of the student is assigned to the fingerprint which is then stored in the internal memory of the Arduino Uno. Fingerprints are considered to be the best and fastest method for biometric identification. They are secure to use, unique for every person and does not change in one’s lifetime. It was our responsibility to implement the fingerprint identification system for faster taking of attendance. This system was implemented in Arduino Uno board.Item DC-DC and AC-DC Zeta and buck converter design and analysis for high efficiency application(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Sakib, Sadman; Khan, Md. Fahim Hasan; Rahman, Md. Ashiqur; Reza, Md. ZamilurThe thesis work is carried out to design and analyze DC-DC and AC-DC converters. Two types of DC-DC converters, buck and zeta, are presented in this book with dc steady state analysis at continuous conduction mode, ac small signal analysis and simulation results. The analysis of DC-DC buck converter includes a switched capacitor buck converter and a switched inductor buck converter. These two converters have been proposed in a previously published article. But, the article did not show the detailed analysis. So, the detailed mathematical model has been developed for these two buck circuits. Another type of buck converter, based on switched inductor-capacitor, is presented briefly in chapter 5. This buck converter has been accepted in an IEEE conference. Two types of zeta converter, switched inductor and modified conventional, are shown in this book. The modified conventional zeta circuit is a new design while the other circuit is taken from a previously published article. The newly developed modified conventional zeta circuit improves the performance of conventional zeta circuit by increasing the efficiency above 95%. A two stage AC-DC converter based on switched inductor zeta circuit is designed and analyzed. The proposed AC-DC circuit improves the power quality compared to the conventional circuit. It raises the efficiency above 95%, increases the power factor (PF) by 6% compared to the conventional circuit and improve the total harmonic distortion (THD) by 2-3% with respect to the conventional circuit.Item Performance Enhancement of Solar Energy using PID controller based DC-DC boost converter(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Anwar, Md. Zahid; Islam, Shehran; Mostafiz, Monwar; Nasim, Sharif WarsiSolar systems, as the name implies, combine two or more modes of electricity generation together, usually using renewable technologies such as solar photovoltaic (PV) and wind turbines. Renewable energy based solar power system is becoming the topic of attraction to the power system designers because of its economic feasibility and environmental friendliness. Solar systems provide a high level of energy security through the mix of generation methods, and often will incorporate a storage system (battery, Fuel cell) or small fossil fueled generator to ensure maximum supply reliability and security. The places where there is no supply of electricity from the main grid and the places where there is pretty high load shedding due to irrigation and other reasons are more viable for renewable energy based solar power station. The main purpose of our thesis is to introduce an approach to design a DC-DC boost converter with constant output voltage for grid connected photovoltaic application system. The boost converter is designed to step up a fluctuating solar panel voltage to a higher constant DC voltage. It uses voltage feedback to keep the output voltage constant. To do so, a PID controller is used as the heart of the control system. It tracks and provides pulse-width-modulation signal to control power electronic device in boost converter. The boost converter will be able to direct couple with grid-tied inverter for grid connected photovoltaic system. Simulations were performed to describe the proposed design. Works were carried out with the designed boost converter which has a power rating of 800 W and 200 V output voltage operated in continuous conduction mode at 5 kHz switching frequency.Item Silicon nanowire anode for lithium ion battery(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Sourav, Md. Shakabul Islam; Rahman, Asfaqur; Hridoy, Kamrul Ahsan; Ahmed, Rubyat RaduanA novel self-supported electrode with long cycling life and high mass loading was developed based on carbon-coated Si nanowires grown in situ on highly conductive and flexible carbon fabric substrates through a nickel-catalyzed one-pot atmospheric pressure chemical vapor deposition. The high-quality carbon coated Si nanowires resulted in high reversible specific capacity (∼3500 mA h g−1 at 100 mA g−1), while the three-dimensional electrode‘s unique architecture leads to a significantly improved robustness and a high degree of electrode stability. An exceptionally long cyclability with a capacity retention of ∼66% over 500 cycles at 1.0 A g−1 was achieved. The controllable high mass loading enables an electrode with extremely high areal capacity of ∼5.0 mA h cm−2. Such a scalable electrode fabrication technology and the high performance electrodes hold great promise in future practical applications in high energy density lithium-ionbatteries.Item Optical fiber for terahertz wave(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Hoque, Shifatul; Rahman, Ziaur; Tajwar, Tasin; Hasan, MahbubulTerahertz radiation occupies a middle ground between microwaves and infrared light waves known as the terahertz gap, where technology for its generation and manipulation is in its infancy. The frequency band of 0.1-10 THz, known as THz band has brought potential applications in many important fields. For wave propagation THz systems use free space as medium. But in free space waves face many difficulties which is very big issue for wave propagation. So we have to use guided transmission instead of unguided transmission. In the mean time many guided transmission line has many kinds of deprivation such as effective material loss, confinement loss, bending loss, dispersion loss, power fraction issue etc. So we had decided to make a porous core fiber which has less losses than other PCF. Mainly we have been inspired from previous papers in which these losses was too much high for THz wave guidance. Then we have designed rotate hexagonal core and octagonal cladding with 8% PML of total fiber radius. This design gives a lower effective material loss and comparatively higher mode power propagation as well as a flattened dispersion gained over the frequency range 0.95-1.25 THz.Item A comprehensive study on smart grid development in OIC Member States(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Hussain, Mohammad; Abdulaziz, MaazGlobal warming, increasing amount of greenhouse gases and narrowness of Ozone layer are the biggest global challenges of 21st century therefore we need green and renewable energy and very efficient use of natural energy resources. Traditional electricity grid is passive, unreliable and inefficient. The generation system is centralized therefore there is very low efficient use of energy resources. Management system, control system and costumer consumption metering system are using very old technologies. Smart grid is a future grid that is equipped with integration of electrical, digital, information and communication technologies .It’s automatic, distributed and intelligent features allow two-way flow of energy and information between power provider and consumers. It provides very efficient power transmission and distribution. In the generation system there is high rate of renewable energy penetration since it’s capability of distributed generation and two-way flow of energy allows each consumer to be a producer as well. Development of smart grid in some OIC (Organization of Islamic Cooperation) member states which have huge national resources such as oil reserves and natural gas and better level of economic development can help them to respond to many challenges, Ensuring the delivery of energy services in line with economic growth in a financially sustainable manner, and increasing access to energy services; Safeguarding the environment and its key natural resources by improving the efficiency of resource management, increasing energy efficiency, and the role of renewable energy. Smart grid makes it possible to integrate the grids of many of these countries into a single grid in order to share power and provide efficient power generation and distribution. In this thesis smart grid concepts, architecture and technologies are demonstrated; the key challenges and opportunities in development of smart grid are discussed; Standardization recommendation from authentic international organization for standardization is given; a scenario of electricity generation and distribution strategies in each country is demonstrate; the current scope of smart grid development in some OIC member states with better development and economic level is studied ; the key challenges and problems that are faced in developing smart grid are discussed; and some recommendations to governments for developing smart grid are given .Item Quantum dot lasers(Department of Electrical and Electronic Engineering, Islamic University of Technology, 2017-11-15) Hossain, Mohammed Eshphaq; Irfan, Muhammad Sami; Hasan, Mehedi; Hossain, AKM SalmanSemiconductor quantum dots have gained considerable research interest in the recent years. Their unique tunable electrical and optical properties make them ideal for applications in transistors, LEDs, lasers and solar cells. In particular their application in semiconductor laser is an area of research that draws considerable interest. In this work, we review the recent advancements in quantum dot laser technology. A brief review of semiconductor nanostructures and quantum confinement effect is presented at the beginning. Various fabrication methods of quantum dots are discussed as well. Secondly, we examined the physical properties of quantum dot lasers along with history and development of quantum dot laser technology and different kinds of quantum dot lasers comparing with other types of lasers. Finally, we describe the rate equation model for quantum dot lasers, simulate the model in MATLAB software package and discuss the results obtained from the simulation
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