Publications 2021

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https://hdl.handle.net/20.500.14170/3707

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Browsing Publications 2021 by Author "Abd-Rahman R."
  • Publication
    Flashover voltage prediction on polluted cup-pin the insulators under polluted conditions
    ( 2021-01-01)
    Salem A.A.
    ;
    Abd-Rahman R.
    ;
    Kamarudin M.S.
    ;
    Othman N.A.
    ;
    Jamail N.A.M.
    ;
    Nuriziani Hussin
    ;
    Haziah Abdul Hamid
    ;
    Rawi I.M.
    The natural pollution which is mainly affected by the weather conditions are the main cause of flashovers on high voltage insulators leading to outages in power systems. In this work, characteristics of flashover for contaminated cup-pin insulators have been studied based on experiential test and a mathematical model. Information from laboratory test combined with new mathematical model results are used to define Artificial Neural Network (ANN) algorithm and Adaptive Neuro-fuzzy Inference System (ANFIS) for calculated the flashover characteristics (current IF and voltage UF). several of experiments and measurement are carried out for 1:1, 5:1, 10:1 and 15:1 ratios of bottom to top surface salt deposit density on contaminated samples (z). Dimensional Analysis Method (DAM) was used to derive new model for the variables which often effective in the flashover phenomenon of polluted insulators. The model was derived by establishment the relationship between flashover voltage UF and current IF, length of pollution layer LP, exposure time t, arc constant A and layer pollution conductivity of insulator σ. The both arc constants A and n is computed using genetic algorithm. Comparative investigates have clearly shown that the approach AI-based method gives the agreeable results compared to the mathematical model.
  • Publication
    Low Concentration Vegetable Oil Based Nanofluid : Dielectric properties, AC Breakdown Voltage and Kinematic Viscosity
    ( 2021-06-11)
    Hussin N.
    ;
    Subri N.A.
    ;
    Azizie N.A.
    ;
    Khalil A.N.M.
    ;
    Jamil M.K.M.
    ;
    Abd-Rahman R.
    ;
    Arshad S.N.M.
    The transformers oil acts as an insulation as well as cooling liquid of a transformer. It is very important that the transformer oil is maintained so that the oil properties are preserved with time. Petroleum-based mineral oil is widely used as insulation oil in transformer due to its excellent insulating qualities and low cost despite its' non-biodegradable and hazardous property. This paper seeks to find an alternative of mineral oil by using palm oil based nanofluids at lower concentration values that match the IEC standards for ester oil. The nanoparticles used in this project are zinc oxide (ZnO) and zirconium dioxide (ZrO2). ZnO has conductive nature while ZrO2 on the other hand shows insulative behavior. Three different concentration value were used which were 0.0015 g/L, 0.0025 g/L and 0.005 g/L which had never been reported before. Tests performed on the samples includes AC breakdown, dielectric properties and kinematic viscosity. Research outcome shows an outstanding result at optimum value in improving the measured properties at these low nanofluid concentrations. Reducing the amount of nanoparticles use also means saving cost and providing a more eco-friendly solution.
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