Now showing 1 - 4 of 4
  • Publication
    Experimental Investigation on Thermal Conductivity of Palm Oil and Zinc Oxide PFAE-based Nanofluids
    Vegetable oil (VO) have been constantly researched as an alternative to the conventional mineral oil (MO) in the application of transformer insulation liquid. VO is deemed as a suitable replacement for MO as they are a renewable source, cheaper in price, and have a high thermal conductivity, high flashpoint, and high breakdown voltage value. In addition, the trending interest in nanofluids has made it possible to further improved the insulating properties of VOs. This paper reports the experimental results of thermal conductivity test of Palm oil-based nanofluids and Palm fatty acid ester (PFAE)-based nanofluids. The nanoparticles used in this work is Zinc Oxide (ZnO) <50nm nano powder and the nanofluid (NF) samples are varied by low, medium and high concentrations. The test was conducted at 9 different temperatures from 25°C to 65°C with 5°C gap. The result shows that a low and medium concentration nanofluid has an improvement in thermal conductivity value, up to 42.6% and 59.5% respectively for palm oil-based nanofluid. Meanwhile, the high concentration palm oil-based nanofluid has lower enhancement in thermal conductivity value at certain temperatures. As for PFAE-based nanofluids, the thermal conductivity value has improved by up to 27% and 14.4% for medium and high concentration respectively. Nanofluids with medium concentration of ZnO, has the highest enhancement in insulating and cooling properties for both palm oil and PFAE-based nanofluids. This observation is supported by the kinematic viscosity value of the mentioned nanofluid.
  • Publication
    Varying the energisation condition to mitigate sympathetic inrush current
    Transformers are generally easy to access and can contribute significantly to entire power system. When a transformer is turned on for the first time, it produces a magnetising inrush current which acts as a starting current. Energisation of transformer has a substantial impact on inrush current and transformer that are connected in parallel. Sympathetic inrush current is a phenomenon that appears when a transformer is switched-on in network whereas the other transformers that was earlier energised. Besides, when sympathetic inrush phenomena occur, the peak and period fluctuate significantly. In this paper, the transformers will be energised in three different ways and each condition will be explored in depth. The operation time of the transformer’s energisation whether it is energised simultaneously or at different times are tested and analysed in terms of their characteristics. It is performed using power system computer aided design (PSCAD) software, starting with a develop model of the energisation and then generate the outcomes. The results of the simulation demonstrate that energising the transformer in different ways can give different effect on the sympathetic inrush current, as well as the variables that affect it and methods for reducing it
  • Publication
    Profiling crowdsourcing practices trend among SMEs in Malaysia
    ( 2021-07-21)
    Mansor M.F.
    ;
    ;
    Ahmad N.H.
    ;
    Abu N.H.
    ;
    Kassim M.A.M.
    Small and Medium Enterprises (SMEs) are the important 'engines of growth' for developed and developing countries. They are the main share of total enterprises and contributes significantly to the Gross Domestic Product (GDP), employment and export. Nevertheless, SMEs remain unachieved the expected success due to grapple with the failure risk, survival downturns and uncertainty environment. To overcome these challenges, the SMEs have to explore the best business strategies i.e crowdsourcing practices for their organisation to boost business performance. Therefore, the objective of this study is to investigate and profiling crowdsourcing practices among Malaysian SME's that possibly could be one of the organisational business strategies to complement resources scarcity and improve business performance. This study also exploring the crowdsourcing practices scenario in Malaysia, crowdsourcing business activities, crowdsourcing platforms and its effect towards business performance. The study employs quantitative approach. The findings revealed that, the crowdsourcing trends showed that SMEs not only crowdsource non-core business activities but they also tend to crowdsource some of core business or complex business activities such as new product development, marketing research and innovation activities to increase organisational capability to overcome internal resources constrains. The study also highlights both practical, theoretical implications, limitation and future study.
  • Publication
    Arcing fault diagnosis using first peak arrival of EM radiation signal
    The objective of this study was to diagnose the arcing fault signals based on the first peak of arrival method using antenna to assess its use as potential arcing fault detection in power system network. Square patch antenna and circle patch antenna were employed for detection on artificial arcing in real environment. First peak of arcing signal arrival was measured through an analysis over a range of time and amplitude signals detected. For accurate results, Discrete Wavelet Transform (DWT) denoising technique was applied to the arcing signals detected as denoising tools. Analysis of first peak of signal arrival time and amplitude were carried out using MATLAB software to measure the changes in signals detected caused by di different placements of antenna. The results revealed that the first peak of signal arrival time, amplitude, type of antenna used and placement of the antenna around arcing source point all reflect the signals measurement.
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