Now showing 1 - 4 of 4
  • Publication
    The effect of lamination thickness of transformer core on the flux and power loss distribution using grain-oriented 3.1% silicon iron
    In this project, the 100kVA three phase transformer core model have been investigated and analyzed for its losses and flux distribution using different thickness lamination of the core built with grain-oriented silicon iron (3.1% SiFe), grade M4. The transformer core has been assembled with 60o T-joint, mitred overlap corner joints using two different thickness of transformer core material, which is 0.23mm and 0.27mm. This research was done with 3D FEM software approaches and experimental methods. From 3D Finite Element Method (FEM), the total magnetic flux density when transformer core assembled with different lamination thickness is obtained. Based on FEM, thinner lamination steel shows better magnetic flux density compared to using thicker lamination steel by percentage of 2.9%. Experimental has been carried out using no load test with arrays of search coil that has been placed to the lamination of the transformer core in order to measure localized and normal flux density distribution and also its odd harmonic content. Localized power loss distribution at the transformer core also done by using thermistor method. Building factor for the transformer core that used thinner lamination steel is better by 2.5% compared to the thicker lamination steel. The experimental results show that when the core flux density increased from 1.0T to 1.8T, the flux distribution in the lamination will show interesting trend at both T-joint and corner joint. The performance at the corner joint shows better result, where high loss will tends to occur more at the T-joint area. The highest losses and flux distribution will occur during 1.8T and the lowest is during 1.0T respectively for both lamination thicknesses. Losses mostly high at the intersection of the joint and will gradually decrease as it travel away from the joint area as indicated by 3D FEM software. Overall, the transformer core that assembled with 0.23mm lamination steel will generate more efficient distribution transformer since it produce lower losses and better flux distribution compared to 0.27mm lamination steel. Therefore, the results obtained by experiment comply with the simulation result obtained by FEM software. In term of economic aspects, large amount of money can be saved when the distribution transformer core been replaced with thinner lamination steel.
  • 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.
  • 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.
  • 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.