Now showing 1 - 10 of 36
  • Publication
    Wind turbine constant voltage controller using modified SHEPWM technique
    The major challenges in designing the controller for wind turbine are fluctuations of the wind speed and the harmonic contents of the output voltage. The fluctuations of the wind turbine speed results in inconsistency of voltage supplied to the inverter which will affect the harmonic of the output voltage. Therefore, this research is dedicated to design a controller consists of a DC/DC boost converter and a DC/AC inverter integrated with the wind turbine system. The controller plays two important roles. Firstly, the controller has to control the consistency of the output voltage of the DC/DC boost converter irrespective of the inconsistency of the input voltage supplied using PI controller. Second, the controller has to generate the firing angles that giving out lesser harmonic to the single phase DC/AC inverter using the Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) switching strategy. The overall system has been designed successfully using MATLAB Simulink software and implemented using real hardware. The results from both simulation and hardware are collected, analysed and compared. For boost converter, the output voltage is in constant 50V even though the input voltage supplied to the boost converter is varies and it is suitable to charge the battery system. For inverter, the hardware is tested with a resistive load and an inductive load to study the performance of the controller when dealing with different types of load. From the results obtained from simulation and hardware, it can be concluded that the designed controller circuit is working well even though the input voltage supplied to the boost converter varies and the output voltage of inverter is very low in total harmonic distortion (THD) nearly 3.6% for THD voltage and 2.1% for THD current.
  • Publication
    Malaria Parasite Diagnosis Using Computational Techniques: A Comprehensive Review
    Malaria is a very serious disease that caused by the transmitted of parasites through the bites of infected Anopheles mosquito. Malaria death cases can be reduced and prevented through early diagnosis and prompt treatment. A fast and easy-to-use method, with high performance is required to differentiate malaria from non-malarial fevers. Manual examination of blood smears is currently the gold standard, but it is time-consuming, labour-intensive, requires skilled microscopists and the sensitivity of the method depends heavily on the skills of the microscopist. Currently, microscopy-based diagnosis remains the most widely used approach for malaria diagnosis. The development of automated malaria detection techniques is still a field of interest. Automated detection is faster and high accuracy compared to the traditional technique using microscopy. This paper presents an exhaustive review of these studies and suggests a direction for future developments of the malaria detection techniques. This paper analysis of three popular computational approaches which is k-mean clustering, neural network, and morphological approach was presented. Based on overall performance, many research proposed based on the morphological approach in order to detect malaria.
  • Publication
    Comparative investigations on different types of inductors in single-phase inverter
    This article organized in two sections where it compares the performance of single-phase inverters using various types of inductors with differences modulation technique of pulse width modulation (PWM). Not all inductors perform the same function, even the inductance value is the same. The study will investigate the capability of each inductor on its performance to convert the unfiltered AC voltage into filtered sinusoidal AC voltage. The drum core and toroidal core inductors were used in this investigation. For both inductors, the performance will be analyzed based on Bipolar and Unipolar switching schemes in a single unit H-bridge circuit. The validation of results are through experimental assessment only and it will be evaluating the shape of sinusoidal AC voltage and the content of total harmonics distortion in the AC voltage for both inductors.
  • Publication
    Analysis of Symmetrical and Asymmetrical Multilevel Inverter using GWO Algorithm
    This article presents a single-phase multilevel inverter with reduced switches technique to generate 9-level output voltage waveform during symmetric operation and 17-level output voltage waveform during asymmetric operation. The generation of firing angles for each power switches are tuned by using the Grey Wolf Optimization technique. The purpose of this study is to investigate the capability of the propose multilevel circuit on handling the different voltage injection to form the symmetrical and asymmetrical operation in a real hardware implementation. The proposed topology only used 10 units of power switches to from 17-level output voltage waveform compared to the conventional multilevel topology which requires 32 units of power switches. The reduction of power switches has significantly reduced the converter size as well as the power consumption for the controller and driver circuit. The feasibility of the proposed technique has been validated using MATLAB/Simulink software and through experimental results. The results will be focused on the harmonic performance and the amount of THD for asymmetrical is much lower compared to the symmetrical configuration.
  • Publication
    Total Harmonic Distortion Comparison Analysis between High-Power Density Inverter and Multilevel Inverter
    The inverter is one of the most common things in converting electrical energy supply and it is a very important concept in the current modern electrical power system to utilize the maximum potential by generating the unit while considering the environment within the surrounding area and avoid pollution is the most ideal concept of energy management. The main purpose of this study is to consider which one of the inverters is more suitable for energy saving. There are two kinds of inverter that have been tested for this research which are the High-power density inverter (HPDI) and Multilevel inverter (MLI). In High-power density inverter (HPDI) it uses electrical components such as Insulated-gate Bipolar Transistor (IGBT) as the main component. As for the Multilevel inverter (MLI) it uses electrical components Metal- oxide-semiconductor field-effect-transistor (MOSFET) as the main component. Both inverters are being implemented and running by using MATLAB Simulink software. Besides that, the result is obtained by comparing the Total Harmonic Distortion (THD), the output of the waveform and energy efficiency for both inverters.
  • Publication
    A review on VFD Control and Energy Management System of Induction Motor for Electric Vehicle
    This growing pattern of energy insufficiency will, of course, intensify in the future. According to the literature, variable frequency drives can save a lot of energy by changing the speed of the electrical motor mechanism (VFDs). The aim of these studies and analyses is to improve the efficiency of the electrical device system by using VFD control techniques. This paper outlines the principle of control mechanisms for induction motor drives, as well as their benefits and drawbacks. This paper is intended to serve as a one-stop shop for researchers interested in the topic. However, there appears to be no comprehensive review of Variable Frequency Drive (VFD) techniques for induction motor (IM) drives to resolve the need for a detailed insight into IM drives. Efficient control policies for induction motor drives provide a great opportunity for energy savings. As a result, research into the optimal operation of induction motor drives is escalating.
  • Publication
    Harmonic Analysis of Three-Phase Asymmetrical Multilevel Inverter with Reduced Number of Switches
    This paper presents an analysis of a three-phase asymmetrical multilevel inverter towards resistive and inductive load testing. The asymmetrical multilevel inverter is chosen over the standard symmetrical multilevel inverter due to its circuit simplicity, cost-effectiveness and better performance as the topology offers a reduction in the number of switches and the improved Total Harmonic Distortion (THD). Whenever different levels of voltage are applied in an asymmetric cascaded H-bridge multilevel inverter, it will increase output voltage levels and reduces the harmonics. The selected topology is the cascaded H-bridge inverter with reduced number of switches and the modulation technique used in this paper intersects a single unit of a sine wave with three carrier signals to produce the PWM pulses for controlling the MOSFETs. The experiment was set up under a lab-scale and using the standard DC power supply. The experimental data for both resistive and inductive loads with modulation indexes of 0.7 and 0.9 are shown to verify the analysis. THD voltage and current are slightly higher for resistive loads than inductive loads. In addition, as the modulation index rises, the value of THD voltage and current decreases.
  • Publication
    Investigation and Performance Analysis of DC-DC Boost Converter System
    This paper presents the analysis of a closed loop DC-DC boost converter for renewable energy applications such as PV. Most of renewable energy resources produce DC voltage that implied with DC-DC converters to convert their input voltage into a higher or lower voltage level accordingly to their application. However, there are numerous types of devices or applications that used renewable energy. Thus, it means the evolution of using a closed loop boost converter system must occur. The closed-loop system DC-DC boost converter is used to step up the low-level DC voltage to a high level of DC voltage. By varying the input voltage, the performance of boost converter in terms of its output voltage can be obtained and analysed. Several studies were conducted and validated with hardware implementation. All the results are recorded and show that various levels of input voltage can be converted into a fixed value of output voltage by using this converter. To emphasise, the boost converter generated 73.33 V output when an input voltage of 12 V. Whereas this experiment is conducted to analyse the boost converter performance so that can consider if this converter is compatible with the IR dryer system.
  • Publication
    Current Sensor Based on Planar Rogowski Coil
    This paper discusses the design and development of current sensor based on planar Rogowski Coil. A Rogowski coil is a toroid of wire used to measure an alternating current through a cable encircled by the toroid. The aim of this study is to design and develop planar Rogowski as a sensor for current measurement and detection using printed circuit board (PCB). The problem of this project is Rogowski Coil (RC) current sensor has same principle as Current Transformer, but the design is different, especially the RC is developed in PCB. Before starting in development of Rogowski Coil current sensor, a few studies are required to review past research on related topic to develop this project. The winding of Rogowski coil current sensor is design by using design software which is EasyEDA to achieve very good sensitivity for wide bandwidth range of frequency at the lowest cost. Finally, the prototype developed is experimented to get the result. The experimental results are discussed and evaluated regarding the performance of the prototype. The highest induced voltage that detected is 55.3 mV and the lowest induced voltage is 11.1mV. The design of Rogowski sensor is significantly shown the best performance of the current sensor in term of sensitivity and bandwidth.
  • Publication
    Performance Analysis of Modified Nine-level Inverter with SHEPWM using an Artificial Bee Colony Algorithm
    This article presents a three-phase modified nine-level multilevel inverter using Artificial Bee Colony Algorithm (ABC) to remove the low order harmonics. Low order harmonics can be fully removed from the output voltage and current waveform by using the proper switching angles. The non-linear equations derived from the Fourier series of the output voltage and current waveform were used to compute the switching angles. The ABC was created specifically for the suggested reduced switch approach topology to solve the nonlinear equation and generate the required switching angles. Simulator tools such PSIM was used to model the circuit, and experimental results were used to evaluate it. The 5th, 7th, and 11th order harmonics will be eliminated, and two modulation indices will be compared, and their performance measured in terms of overall harmonic distortion. THD results will be shown for modulation indexes of 0.58 and 0.83.