Now showing 1 - 10 of 16
  • Publication
    Multiple Partial Discharge Signal Classification Using Artificial Neural Network Technique in XLPE Power Cable
    ( 2023-02-01)
    Halim M.I.A.
    ;
    Razaly N.Z.M.
    ;
    ; ;
    Auni W.N.
    ;
    ; ; ;
    Mas’ud A.A.
    According to partial discharge (PD) damage in the electrodes that are not entirely bridging, the presence of PD in the high voltage (HV) power cable might lead to insulation failure. PD defects can damage cross-linked polyethylene (XLPE) cables directly, which is one of the most critical electrical issues in the industry. Poor workmanship during cable jointing, aging, or exposure to the surrounding environment is the most common cause of PD in HV cable systems. As a result, the location of the PD signals that occur cannot be classified without identifying the multiple PD signals present in the cable system. In this study, the artificial neural network (ANN) based feedforward back propagation classification technique is used as a diagnostic tool thru MATLAB software in which the PD signal was approached to determine the accuracy of the location PD signal. In addition, statistical feature extraction was added to compare the accuracy of classification with the standard method. The three-point technique is also an approach used to locate PD signals in a single line 11 kV XLPE underground power cable. The results show that the statistical feature extraction had been successful classify the PD signal location with the accuracy of 80% compared to without statistical feature extraction. The distance between PD signals and the PD source affected the result of the three-point technique which proved that a lower error means a near distance between them.
  • 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.
      6  25
  • Publication
    Selective Harmonic Elimination of Five Level Cascaded H-Bridge Inverter Using the Newton-Raphson Technique
    ( 2021-07-26) ;
    Kasdi N.S.
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    ;
    Mashagba H.A.
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    ; ;
    Sulong Syahmi M.M.
    Multilevel inverter becomes an alternative for high power and medium voltage applications recently and is more popular in renewable energy. The cascaded H-bridge multilevel inverter is more suitable for the Photovoltaic application because it acts as a separate DC source for each bridge. This paper presents a selective harmonic elimination (SHE) modulation for single-phase cascaded H-bridge (CHB) five level inverter. The optimum angle of the transcendental equations is solved the fundamental and harmonic elements using the Newton-Raphson (NR) process. The proposed selective harmonic elimination (SHE) scheme is tested using MATLAB/Simulink simulation. These simulation results are then verified through experiment using microcontroller. The proposed SHE is efficient in eliminating the 5th order harmonics and producing a higher quality output waveform with a better harmonic profile.
      2  23
  • 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.
      2  2
  • Publication
    Harmonic Analysis of Modified Nine-level Inverter with SHEPWM using Grey Wolf Optimization
    This paper presents the nine-level multilevel inverter with reduces switch technique using Grey Wolf Optimization (GWO) methods on eliminating the low order harmonics. Using the appropriate switching angles, the low order harmonics can be eliminated completely from the output voltage and current waveform. The switching angles were calculated using the non-linear equations derived from the Fourier series of the output voltage and current waveform. In this paper, GWO algorithm was developed to solve the nonlinear equation and generate the appropriate switching angles specifically for the proposed reduced switch technique topology. The circuit were simulated using PSIM and evaluate based on experimental assessments. The targeted low order harmonic to be eliminated are the 5th, 7th and 11th and two modulation indices will be compared and observed it performance in term of value of total harmonic distortion. The THD results for modulation indexes of 0.7 and 0.82 will be displayed. For modulation index 0.7, simulation yields 7.52% and experimental yields 6.23%. The simulation result for modulation index 0.82 is 5.82% and the experimental result is 4.69%.
      1
  • Publication
    Review Article: Voltage Balancing Method for Battery and Supercapacitor
    This paper examines several existing voltage equalizers techniques for energy storage system, with a focusing on batteries and supercapacitors. Due satisfy the demands, energy storage cells are often coupled in series/parallel. However, divergence of voltage distributed among cells produces the problems of voltage imbalance that affecting the ageing of energy storage system and solved through equalizers. Several assessments from features of topologies in voltage balancing circuit supplied primarily based total on a few attentions’ just like the effectiveness in balance and components. Voltage balancing is essentially separated into two categories: passive and active equalizers. Therefore, this paper studied and reviewed several topologies from both equalizer types with the sample result to verify the topology performance.
      15  28
  • Publication
    The effect of amplitude modulation index on harmonic distortion in unipolar SHEPWM inverter
    The appearance of low order odd harmonic in the AC power line can be mitigated by projecting a proper switching angle during the conversion of the inverter. The switching angles can be obtained by solving the numerical nonlinear equation using numerous solving techniques and algorithms. Several studies shows the value of harmonic significantly increase whenever the amplitude modulation decrease for the SPWM switching scheme of the inverter. However, this topic has not yet covered in the single-phase SHEPWM inverter. This paper is to study the effect of the amplitude modulation index towards the harmonic distortion in the SHEPWM switching technique. To solve the numerical equations, MATLAB code is used to produce the specific switching angles to drive the inverter by solving the numerical equations. The validation of results thru hardware implementation using EZDSPTMS320F28335 to produce the digital signal for controlling the inverter. The targeted low order harmonic to be eliminated are the 3rd, 5th and 7th and three four amplitude modulation indices will be compared and observed in term of total harmonic distortion. The THD results for amplitude modulations 0.6, 0.7, 0.8 and 0.9 are 17.50%, 15.10%, 13.30% and 10.63%.
      21  33
  • Publication
    Harmonic elimination simulation of seven level Cascaded H-Bridge Inverter Based on Newton Raphson method
    Multilevel inverters for high-power applications are arising as the new breed of power converter options. Usually, they combine the waveform of the staircase voltage (from many dc sources) that has reduced the harmonic content. The selective harmonic elimination (SHE) by using Newton-Raphson method is proposed to apply for 350 W infrared dyer system. The analysis covers the scope for multilevel inverter single-phase cascaded H-bridge (CHB). The proposed SHE scheme is run using MATLAB/Simulink simulation. The results of these simulation is then compared to a 36 V output inverter hardware. The proposed SHE effectively removes the lowest-order harmonics and delivers a higher quality output waveform with a better harmonic profile.
      3  23
  • Publication
    Selective harmonic elimination pulse width modulation for five-phase cascaded multilevel inverter using non-notch and notch switching technique
    As in this era, the conversion of DC power to AC power is a necessity in the power system in order to make useful of renewable energy. The most commonly used switching mechanism is known as inverter or multilevel inverter. However, this switching may cause harmonics. Harmonics usually occur in a power system due to distortion, which can cause a lot of unwanted problems. It could appear either in voltage or in current waveforms. Minimization of Total Harmonic Distortion (THD) is necessary in order to maintain a good power system. This paper introduces selective harmonic elimination pulse width modulation for five-phase cascaded multilevel inverter. The proposed switching technique for five-phase cascaded multilevel inverter used in this research is non-notch and notch switching technique. Particle Swarm Optimization (PSO) algorithm was used as an optimization technique to find switching angles for non-notch and notch switching techniques. In addition, the simulation of a seven-level five-phase cascaded multilevel inverter for both switching operations is carried out in the PSIM environment. The results show that the non-notch switching was able to eliminate lower order harmonics up to the 7th harmonic. In addition, the notch switching technique managed to eliminate lower order harmonics up to the 21st harmonic for 3/3/3 switching distribution.
      4  40
  • 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