Now showing 1 - 9 of 9
  • Publication
    Comparative Study of Multiphase 5-Level Cascaded H-Bridge Multilevel Inverter System
    ( 2022-01-01)
    Zawawi M.N.M.
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    Talib M.H.N.
    In terms of cost and structural design, the cascaded H-bridge multilevel inverter (CHBMLI) has a significant advantage over diode clamped and capacitor clamped multilevel inverters. The total harmonic distortion (THD) of a 5-level CHBMLI system for three different phases (single-phase, three-phase, and six-phase system) is studied and compared in this work. As switching angles play a role in lowering THD, the switching angles for a 5-level CHBMLI are evaluated using four specific switching angle methods in the initial section of this paper. In the simulation of single-phase system, these angles are being utilized. The angles with the lowest THD value are chosen for three-phase and six-phase system simulation. Based on the findings, the higher phase of 5-level CHBMLI is more efficient in decreasing harmonics.
  • Publication
    Harmonics elimination of reduced switch multilevel inverter using henry gas solubility optimization algorithm
    (Iran University of Science and Technology, 2025-06) ; ; ;
    This study introduces a pioneering method to enhance the efficiency and effectiveness of three-phase five-level reduced switch cascaded H-bridge multilevel inverters (CHB MLI) by employing the Henry Gas Solubility Optimization (HGSO) algorithm. Targeting the selective harmonic elimination (SHE) technique, the research emphasizes the optimization of switching angles to significantly reduce total harmonic distortion (THD) and align the fundamental output voltage closely with the reference voltage. Central to this exploration are three distinct objective functions (OFs), meticulously designed to assess the HGSO algorithm’s performance across various modulation indices. Simulation results, facilitated by PSIM software, illustrate the impactful role these objective functions play in the optimization process. OF1 demonstrated a superior ability in generating low OF values and maintaining a consistent match between reference and fundamental voltages across the modulation index spectrum. Regarding the reduction of THD, it is crucial to emphasize that all OFs can identify the most effective switching angle to minimize THD and eliminate the fifth harmonic to a level below 0.1%. The findings highlight the potential of HGSO in solving complex optimization challenges within power electronics, offering a novel pathway for advancing modulation strategies in CHB MLIs and contributing to the development of more efficient, reliable, and compact power conversion systems.
  • Publication
    THD analysis for symmetrical five level and seven level cascaded multilevel inverter
    Total Harmonic Distortion (THD) is one of the problems in the multilevel inverter. This paper discussed a brief review of THD in different cascaded H-bridge multilevel inverter topologies of five levels and seven levels at the output waveforms. The five levels inverter contains eight switches while seven levels inverter used twelve switches. Each single H-bridge inverter circuit is fed by equally independent DC source for both inverters. The inverter uses MOSFET as the switching point and acts as the controller for a fundamental switching operation. The switching value has been set at the gating block to control the operation of the MOSFET switching. Several waveforms and simulation findings are provided to validate the quality of the proposed topology.
      1  43
  • Publication
    Comparative Analysis of 5-level Multilevel Inverter with Reduced Switched Topology
    A new topology for the single phase 5-level multilevel inverter is proposed in this paper. Using multiple semiconductor switches and lower-level DC voltages as input, a multilevel inverter generates more than two voltage levels to achieve high efficiency, smoother, and less distorted alternating voltage. The conventional 5-level multilevel inverter requires 8 switches in configurations of two cascaded H-bridge resulting in cost addition as well in generating more losses in the circuit. The proposed topology offers the same 5-level output voltage with lesser power switches resulting in cost-effectiveness as well as improve the circuit complexity. The proposed topology is simulated using PowerSim software to testify its functionality, performance, and validation. A comparative of harmonic distortion between the conventional and the proposed topology is reported.
      28  4
  • Publication
    Multiple switching pattern for a modified reduce switch multilevel inverter: A comparison analysis
    A primary concern of multilevel inverter is its capability to produce desired alternating voltage close to sinusoidal at the output, using multiple sources of DC voltage input. Mostly a multilevel inverter is used to generate the AC voltage from DC voltage. The aim of this paper is to investigate the output of 9 level multilevel inverter by modifying the conventional 5 levels H-bridge cascade multilevel inverter. The proposed design intending to reduce the number of switches from 16 switches to 10 switches. Implementation of different switching pattern methods; equal phase (EP), half equal phase (HEP), half height (HH) and feed forward (FF) and the related expression are presented in this paper. In the result section shows a different percentage of total harmonic distortion achieved. Out of all 4 methods, HH method suppressed distortion wave the most and resulted in the lowest THD in the proposed inverter. This paper shows that by reducing the number of switches in multilevel inverter structure maintains the same quality output as the conventional H-bridge topology. Furthermore, the manipulation of the switches firing angle contribute in decreasing the system THD.
      2  41
  • Publication
    A Dragonfly Algorithm Application: Optimizing Solar Cell Single Diode Model Parameters
    This paper provides an overview of optimizing solar cell single diode parameters using Dragonfly Algorithm. The 57 mm diameter commercial (R.T.C. France) silicon solar cell measurement data are taking as the data source for the optimization process. The results produced are compared with NM-PSO and IJAYA algorithms to observe the efficiency, accuracy and reliability of the proposed approach.
      3  50
  • Publication
    Performance Analysis of a Switched-Mode Flyback DC-DC Converter with Influence of Non-Ideal Switching Devices
    ( 2023)
    Shazlin Shafiqah Shamsul Kamar
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    This paper approach for the performance analysisof a dc-dc flyback converter for low power application. Modelling is done with parasitic components for non-ideal flyback converter. Ac and dc input characteristic of the flyback converter are analysed and investigated by PSIM simulations and calculations. The influence of parasitic effects in converter components on input characteristic is studied in continuous conduction mode (CCM).The results of the calculation based on analytical formula and averaged models are in a good accordance with PSIM simulations and calculation. The goal of this project is to compare an ideal and non-ideal condition in order to see the effect on the efficiency and ability of the converter to control the output voltage. The converter is expected to be operated in continuous conduction mode at all time and focus application islow power application that less than 100W.
      4  9
  • Publication
    An analysis on power quality measurement and monitoring techniques for nonlinear load
    (Universiti Malaysia Perlis (UniMAP), 2008-03-15)
    Shahrul Ashikin Azmi
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    Electric power quality is an aspect of power engineering that has been with us since the inception of power systems. The measurement of the quality of the electric power in a network is therefore becoming an urging need especially in a deregulated electricity market. In the paper, the types of power quality variation are described and the method of characterizing each type with measurements are presented. By using the advances of power quality monitoring equipment and tools, analysis on power quality measurement result are described. The increased amount af data being collected requires more advanced analysis tools. power quality monitoring has advanced from strictly problem solving to ongoing monitoring of system performance.
  • Publication
    A study on voltage sag in industry system with adjustable speed drive
    The awareness of electric power quality has increased over the past decade as electronic equipment has become more susceptible to power disturbances. The most distruptive power disturbances is voltage sags. Voltage sags produce an important effect on the behavior of adjustable speed drives (ASD's). Tripping of ASD is one of the greatest voltage sag problem, causing motor to stop with the resulting loss of time and production, or damaged equipment may cause significant economical loses. This paper is focused on the effect of voltage sags on adjustable speed drive (ASD) which commonly used in industry system. Voltage sags are normally used described by magnitude variation and unbalanced (asymmetry). These factors are important to determine the behavior of ac motor drive during sags. A VSI (Voltage Source Inverter) driving a three-phase induction motor is analyzed through digital simulation. Simulation on sag depth and three types of voltage sags which are based on voltage sag classification, with an emphasis on the changes dc bridge voltage, rms inverter voltage and motor speed were done. Thus, voltages and speed measurement are obtained. Simulation result clearly show that the different types of sags and sag depth would cause dc-link voltage variation and finally result in motor speed changes.