Now showing 1 - 10 of 49
  • Publication
    Bandwidth and gain enhancement of a circular microstrip antenna using a DNG split ring resonator radome
    ( 2019-06-01)
    Rasheed O.
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    Soh Ping Jack
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    Jamlos M.
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    This paper present the design of a circular patch microstrip antenna with enhancement in terms of bandwidth and gain using a dielectric double negative (DNG) split ring metamaterial radome. This radome is positioned on top of the CP antenna operating from 5.2 GHz to 6.4 GHz. The metamaterial radome comprises of two alternate split rings of negative permittivity, permeability and refractive index. The circular microstrip antenna bandwidth of 430 MHz has been realized by the presence of DNG metamaterial radome compared to 220 MHz without the radome. The gain has been increased as well from 1.84 dBi to 3.87 dBi.
  • Publication
    Lightning Impulse Voltage Stresses in Underground Cables
    Underground power cables are crucial for transmission and distribution. Lightning can stress their insulation, but not directly. So, impulse cable testing is studied. This research examines the cable's transient response to standard and non-standard lightning impulse voltage waveforms. MATLAB Simulink was used to model a 132 kV wire with standard and non-standard impulse voltages. The IEC60060-1(2010) lightning impulse test uses a conventional waveform impulse voltage with a front time and a tail time of 1.2/50μs half value, while the non-standard test uses a front time and a tail time of 0.8/12s half value. Non-standard impulse waveforms are more accurate than standard waveforms. The impulse test voltage is four to five times the underground cable's operational voltage and must withstand five applications without damage. Standard and non-standard impulse waveforms are injected with 132 kV and 550 kV to evaluate insulation failure or damage. Standard lightning and non-standard impulse voltage waveforms do not cause insulation failure or damage. When 132 kV and 550 kV are introduced into the normal and non-standard lightning impulse waveforms, the overshoot voltage increases. The peak voltage of a non-standard 550 kV impulse voltage waveform exceeds the IEC impulse withstand voltage. The finding shows that non-standard impulse voltage waves create increased cable voltage stress.
  • Publication
    Design of investment detection in fish cultivation uno arduino based
    ( 2022-02-22)
    Arnawan Hasibuan
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    Asran Asran
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    Rizky Ramadhana Sembiring
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    ; ;
    Fish farming is a job that many Indonesian people do, especially in villages. The nature of fish that is able to adapt quickly to transfer from pond to pond makes many residents choose to breed fish over other livestock. Many types of fish can be cultivated well, but most people choose to cultivate goldfish. Goldfish have an economic value that is quite tempting for the community. There are some fish that have a higher economic value, but people are more extra in maintaining them, for example in terms of feed. Goldfish can be fed only when the sun is hot. If the sun does not come out, then the goldfish should not be fed because it can cause the fish to die. Besides that, goldfish only need water flowing into the pond for fish oxygen. The number of people who breed fish, there are also many irresponsible people. The reason is, when the fish begin to grow up, many fish begin to disappear, making people nervous and hot. Based on the above problems, it provides a very potential opportunity to create a tool that can overcome community unrest. Fish farming theft detection tool which is an innovative tool to overcome or find out the perpetrators of theft. Thus, hopefully the tools used can reduce the risk of stealing fish and reduce the losses of fish cultivators.
  • Publication
    Partial discharge signal measurement based on stand-alone and hybrid detection technique for power transformer
    Partial discharge (PD) is a phenomenon that causes failures in high voltage (HV) components due to the degradation of insulation. Before an interruption or fault occurs, early detection of insulation degradation is essential. However, the long-term effect of PD will lead to the failure of the power system. This is important to control and diagnose the health of the HV power equipment such as power transformer. The main issue when measuring PD is the accuracy and sensitivity of the PD detection technique. This paper consists of two parts which are classification of the PD detection technique and hybrid detection technique. In this paper, an overview of the detection technique for power transformer including optical detection, chemical detection, electrical detection, electromagnetic detection, acoustic emission detection and hybrid detection technique is presented. The hybrid detection technique is based on combining two or more stand-alone detection technique. Based on this review, the hybrid detection technique showed that the advantages of performance in terms of sensitivity and accuracy for detecting the PD in power transformer.
  • Publication
    Partial Discharge Rise Time Characteristic based on Experimental Measurement in Power Cable
    ( 2023-01-01)
    Hashim M.H.
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    ; ; ;
    Jamal A.
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    Aziza N.
    This study presents a comprehensive investigation into the rise time characteristics of partial discharges (PD) in cable insulation through experimental measurements. Partial discharges are a critical phenomenon in high-voltage systems, serving as an early indicator of insulation degradation. Understanding the rise time of partial discharges is essential for assessing the severity of insulation defects and ensuring the reliability of power cable systems. The experimental setup involved controlled conditions to induce partial discharges in cable samples, allowing for precise measurement and analysis of the rise time. The study explores the correlation between rise time and different factors such as cable design, insulation material, and defect type. Results indicate that the rise time of partial discharges exhibits distinct patterns based on these factors, providing valuable insights into the nature of insulation defects. The findings contribute to the development of effective diagnostic tools for condition monitoring in power cable systems, ultimately enhancing the reliability and safety of electrical infrastructure.
  • Publication
    Fabrication and simulation of silicon nanogaps pH sensor as preliminary study for Retinol Binding Protein 4 (RBP4) detection
    In this research, a silicon nanogap biosensor has the potential to play a significant role in the field of biosensors for detecting Retinol Binding Protein 4 (RBP4) molecules due to its unique nanostructure morphology, biocompatibility features, and electrical capabilities. Additionally, as preliminary research for RBP4, a silicon nanogap biosensor with unique molecular gate control for pH measurement was developed. Firstly, using conventional lithography followed by the Reactive-ion etching (RIE) technique, a nanofabrication approach was utilized to produce silicon nanogaps from silicon-on-insulator (SOI) wafers. The critical aspects contributing to the process and size reduction procedures were highlighted to achieve nanometer-scale size. The resulting silicon nanogaps, ranging from 100 nm to 200 nm, were fabricated precisely on the device. Secondly, pH level detection was performed using several types of standard aqueous pH buffer solutions (pH 6, pH 7, pH 12) to test the electrical response of the device. The sensitivity of the silicon nanogap pH sensor was 7.66 pS/pH (R² = 0.97), indicating that the device has a wide range of pH detecting capacity. This also includes the silicon nanogap biosensor validated by simulation, with the sensitivity obtained being 3.24 μA/e.cm² (R² = 0.98). The simulation of the sensitivity is based on the interface charge (Qf) that represents the concentration of RBP4. The results reveal that the silicon nanogap biosensor has excellent characteristics for detecting pH levels and RBP4 with outstanding sensitivity performance. In conclusion, this silicon nanogap biosensor can be used as a new electrical RBP4 biosensor for biomedical diagnostic applications in the future.
  • Publication
    Piezoelectric Sensor using PZT Material for Partial Discharge Detection on Power Transformer
    ( 2020-07-09)
    Alleef Abd Jalil M.
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    Nurul Auni Wan Mohammad W.
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    Zaidi Abdullah A.
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    This paper presents an analysis of acoustic emission (AE) detection technique for partial discharge (PD) on power transformer using piezoelectric sensor. The AE PD detection technique using piezoelectric material is one of the popular method due to its low cost and compact size. A matching resonant frequency of AE sensor with PD signal which in range 10 kHz to 300 kHz is an important factor for this technique. An AE sensor that have a resonant frequency match with PD signal able to give an optimal performances. Therefore, a simulation on different dimensions of lead zirconate titanate (PZT) AE sensor using finite element method (FEM) is conducted in order to determine the performances in terms of resonant frequency, total displacement and generated voltage. The length of AE sensor is varied from 2 mm to 30 mm in order to reveal the influence of length dimension against generated voltage. Based on the obtained results, that 2 mm length of AE sensor able to generate voltage of 3.01 x10-5 mV at resonant frequency of 113.58 kHz which can be proposed toward PD detection on the power transformer.
  • Publication
    Effect of installation of distributed generation at different points in the distribution system on voltage drops and power losses
    ( 2021-05-03)
    Hasibuan A.
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    Nrartha I.M.A.
    The main purpose of this paper is to analyze the impact of different positions of different DG penetrations on bus voltage profiles and channel power losses. The main classification can be done by putting DG on the most critical bus, the closest bus to the most critical but critical bus too, the closest bus to the feeder but critical too, and the furthest from the feeder but critical too. Installing a distributed generation in a distribution network can significantly affect the power system. The effect depends on DG allocation of the distribution network. Implementation of this approach has been made with the IEEE 34 bus standard at different points. DG placement site selection method based on buses decreased voltage over the limit permitted. Simulation results from a case study on the IEEE 34 bus standard system show that the voltage profile on each bus and the loss of system power will be different when compared to the DG installation at different points.
  • Publication
    Effect of RTV coating on the electrical performance of porcelain insulator string under dry condition
    (IOP Publishing, 2020) ; ;
    Z C M Kasa
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    M A M Piah
    Pollution flashover is one of the primary reasons cause to power system failure in Malaysia. The presence of accumulation on the porcelain insulator surface reduces the electrical performance and also causes the failure of insulation in transmission and distribution lines. This research presents a study on the effect of Room Temperature Vulcanize (RTV) coating on the performances of a string porcelain insulator and their impact on environmental contamination. An attempt has been made to simulate the electric field distribution of 33 kV insulators using the finite element method (FEM). From the simulation results, the maximum electric field distribution is obtained at the pin insulator of a clean insulator, while the cap insulator indicated the minimum electric field. With the existence of the contamination layer, the electric field distribution of the porcelain surface results in a reduction trend.