Mohamad Zhafran Zakariya
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Preferred name
Mohamad Zhafran Zakariya
Official Name
Mohamad Zhafran , Zakariya
Alternative Name
Zakariya, M. Z.
Main Affiliation
Scopus Author ID
57214778495
Researcher ID
EIN-5517-2022

Research Output

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  • Publication
    A Systematic Review on Cascading Failures Models in Renewable Power Systems with Dynamics Perspective and Protections Modeling
    ( 2023-01-15)
    Mohamad Zhafran Zakariya
    ;
    Teh J.
    Cascading failure in renewable power systems is a hot topic that attracts most researchers worldwide. This paper discusses the phenomena of blackout and cascading failure in terms of definition, causes, and past events worldwide. This paper also compares the models in terms of features, limitations, computational speed, and test bus for assisting the tradeoff analysis. Benchmarking among the models and potential test buses to be utilized for cascading failure analysis considering the high penetration of renewable power systems, are also included in this paper. The authors propose tradeoffs between the existing cascading failure models and solutions to achieve high accuracy and reduce computational complexity. Furthermore, this paper also compares the statics versus dynamics model methodology and the parameters involved during the simulation, corresponding to the latest challenges in protection systems. This paper also discusses the emerging challenges of cascading failure with an emphasis on the aspect of dynamic models, renewable energy, and the reliability of power systems. Due to the emerging problems that arise with the high penetration of renewable energy, grid-forming technology is the solution to study the impact of renewable energy on cascading failure. Researchers must develop a sophisticated dynamic model with high-speed computational time to realize online monitoring, prediction, and mitigation of blackouts becomes possible.
  • Publication
    Modeling and simulation of high frequency micro-transformer using COMSOL multiphysics software for power electronics applications
    ( 2015)
    Mohamad Zhafran Zakariya
    This thesis presents the optimization study of parasitic components in micro-transformer based on the analysis of simulation results. Micro-fabricated transformer operates in high range of frequency is one of the main component in electronic applications related to DCDC converter. The approaches in this project are to design and simulate the winding structure with different configurations, and then analyzing the result of parasitic components by using COMSOL Multiphysics software through Finite Element Method (FEM) in order to obtain the lowest possible result of leakage and mutual inductance. Modeling of micro-transformer, mainly covers most part of miniaturization of the magnetic component through the use of micro fabrication techniques, which consists the materials such as copper for winding structure and silicon oxide for substrate. The proposed method is to model a 1:1 ratio of micro-transformer that can be operated at the range of frequency between 100MHz to 1GHz. Simulation in two-dimensional (2-D) is implemented in order to determine the result of current density and parasitic components in various windings designs while the simulation in three-dimensional (3-D) is utilized to obtain the result of windings voltage and the flow of magnetic flux. Different number of turns with similar thickness to turn ratio shows the independent relationship between mutual and leakage inductance. Track width ratio of copper coils shows the significant changes for result of mutual inductance. As a conclusion, central composite design (CCD) shows that the factor of -2,2,2,-2 has the lowest and optimum result of leakage and winding resistance while track width ratio of 1.2 has the lowest result of inductance at 1 GHz with percentage errors of parasitic components between 2.804% and 16.526%.
  • Publication
    Piezoelectric Array Configuration Technique into Enhance Power Catchment for Sound Energy Harvester System
    ( 2020-11-18)
    Liew Hui Fang
    ;
    Rosemizi Abd Rahim
    ;
    Muhammad Izuan Fahmi Romli
    ;
    Mohamad Zhafran Zakariya
    ;
    Junaidah Ali Mohd Jobran
    ;
    Norhanisa Kimpol
    The objective of this study is to explore the harvest maximum output changes occurs in piezoelectric transducer when connected in different configuration to produce highest electricity consumption and generate sound energy harvesting system. Acoustic energy is a type of environmental energy source that can be extracted and converted into electrical energy for small-scale energy applications. In this study, the corresponding load resistance for single piezoelectric transducer is 4.5 k$\Omega$, together with a constant vibration source at a frequency of 68 Hz and a 1-g acceleration. The performance of output voltage and power of piezoelectric are evaluated and the optimum output is measured by depending on the connection of the piezoelectric transducer arrangement into series, parallel and series, and parallel which stimulated using Proteus software. The experiment result presented that, when have single piezo, 5 piezo connected in series, and 5 piezo connected in parallel, the output powers are 1.664 mW, 1.671mW and 7.676 mW, respectively. During the combination series and parallel connections, the output power of 3S1P piezo increases to 5.05mW. In a parallel configuration, the output voltage that produced is much higher than a piezoelectric transducer arrangement connected in series connection. The piezoelectric transducer that connected in parallel configurations increases its voltage output from 2.83 V to 13.05 V with the same polarity. The arrangement of piezoelectric transducer in parallel configuration is affordable, with its higher production of a higher power output compared to the arrangement of piezoelectric transducer in series connection. Whereas in terms of power output, the maximum power remains constant in the range of 1.665 to 1.671 mW when three transducers are in series configuration connection with the same polarity. In conclusion, the proper implementation of the piezoelectric array configuration is needed in order to operate the minimum energy for low load devices and promise to accomplish generated optimum power output in harvester system.
  • Publication
    Maximum efficiency scheme using superimposed and Taguchi method wireless charging for mobile phone
    ( 2020-01-07)
    Hanif M.H.M.
    ;
    Muhammad Izuan Fahmi Romli
    ;
    Wai C.L.
    ;
    Muhammad Zaid Aihsan
    ;
    Aminudin A.
    ;
    Zhe L.W.
    ;
    Mohamad Zhafran Zakariya
    The magnetic resonance inductive coupling energy transfer from transmitter to receiver is designed in this project through magnetic inductive coupling. The transmitter sends energy through induction to the electrical devices from the transmitter to the receiver and then stores the energy in the batteries. Because the transmitter coil has a gap with the receiver coil. This wireless charging using two methods to show the output, first using the Taguchi Method and second using Superimposed Technique. The Result shows that output voltage must high than the input voltage and the same at secondary coil because using the same number of turns. The output voltage at the voltage regulator shows the output must in 5 Volts to charging the mobile phone with high efficiency.