Now showing 1 - 10 of 27
  • Publication
    The effect of semi-conductive and non-conductive nano particles in sunflower oil based insulation
    ( 2020-01-07) ;
    Kwong Yeaw L.
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    Kamarol Mohd Jamil M.
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    Ainanie Azizie N.
    Following the improvement of technology, more and more alternatives are introduced to improve the insulation material and one of them is the nanotechnology. Research had been done which confirm the enhancement of the transformer oil upon adding nanoparticles in term of dielectric strength, viscosity, relative permittivity and others. In this research, semi-conductive (ZnO) and non-conductive (ZrO2) nanoparticles with weigh to volume ratio of 0.05g/l are added to the sunflower oil based insulation and the effects are observed. The relative permittivity of added ZnO is higher compare to ZrO2 in mineral oil. The situation is opposite as ZrO2 yield higher permittivity with sunflower oil. In term of breakdown voltage, the addition of ZnO shows a better dielectric strength compare to ZrO2. The kinematic viscosity is also increase when both nanoparticles are added in which ZnO contributes a higher value.
  • Publication
    Impact of Vibration Exciter on the Partial Discharge Characteristics in XLPE Cable
    ( 2023-01-01)
    Laili M.S.
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    Abdul Halim M.H.A.
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    Isa M.
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    Zakaria Z.N.B.
    In power transmission, the durability and efficiency of power cables are significantly influenced by mechanical stresses. Mechanical stresses like vibration, torsion, and bending can cause fatigue in power cable insulation, leading to cracks and partial discharge. This phenomenon can affect the insulation performance of the cable. The study aims to correlate the relationship between vibration and PD, and how vibration strength and frequency influence PD occurrence. The measurements used a vibration exciter to simulate environmental vibration of 30 Hz, 50 Hz, and 70 Hz. A 20 pC PD signal was injected to the XLPE cable and the measurements were measured by HFCT and Rogowski coil sensors. The results showed a significant increase in the amplitude of the PD charge when subjected to high-frequency vibrations.
  • Publication
    A study on copper and galvanized grounding performance using palm oil fuel ash as new additive material
    ( 2020-01-07)
    Faudzi A.H.M.
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    Ahmad N.A.
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    Afrouzi H.N.
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    This paper aimed to study the improvement of grounding performance by reducing the grounding electrode resistance using palm oil fuel ash as the backfill. This is achieved by mixing the soil with a specific portion of palm oil fuel ash and obtains the grounding electrode resistance value by using Three Pin Method. In order to obtain the grounding electrode resistance, the mixture of palm oil fuel ash and soil were compacted and installed with electrodes. Two types of electrodes were connected to measuring device which is Kyoritsu Digital Earth Tester Model 4105A and grounding electrode resistance values were displayed. The two types of electrodes used in this study were copper and galvanized steel electrodes. It was found that by adding palm oil fuel ash to the soil, the grounding performance can be improved to at least 90% and above for both copper and galvanized steel electrodes. The palm oil fuel ash is very effective in improving the grounding performance at low cost and environmentally friendly.
  • Publication
    An experimental work on effect of bending down conductor with reinforced concrete
    Down conductor is one of the pivotal parts of the Lightning Protection System (LPS) that diverting the lightning current captured by the air termination system to the earth termination system in each protected structure. A straight down conductor, is ideally suited for the best-case scenario regarding reliability and safety protection. One to aesthetical aspects, down conductor is undesirably bent in most current buildings. However, only the primary bare type of a down conductor is undergone such process, and bent at a certain degree which depending on the structure itself. Hence, this study is to investigate the bending degree effect on down conductors, by looking at breakdown voltage around the bent area with the presence of concrete wall and reinforcement bar. This experimental work conducted on a reduced scale of reinforced concrete which tested with high impulse voltage. It was determined that the bending down conductors has a significant effect on the bent (vertex) area with the interaction of concrete wall and reinforcement bar.
  • Publication
    Analysis of wavelet transform de-noising technique based on measured lightning return stroke electric field
    ( 2021-05-03) ;
    Ab Kadir M.Z.A.
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    Izadi M.
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    Hamzah M.N.
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    Wooi C.L.
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    Anuar A.
    This paper presents a difference type of wavelet transform de-noising technique based on measured lightning electric field. The lightning electric fields captured by two parallel plats sensor and the signal were analyses accordingly. In engineering application, lightning stroke current parameter will relate with electric fields and these parameters can be recognized by direct and in-direct measuring method. Therefore, measuring lightning electric fields (LEF) using parallel plate was done by many researchers. However, measuring LEF has many disturbances such as noise from other apparatus and other device. Therefore, de-noising of LEF signal is important to get useful signal for further research. For this reason, the Centre for Electromagnetic and Lighting Protection Research (CELP) group has been working on a research program to study and characteristic lightning using de-noising technique in order to process and analyse the radiated LEF produced during flash happens. Only three types of wavelet transform are selected and there are Daubechies, Symlets and Coiflets wavelet. The result will be discussed and the best will be selected based on the measured signal.
  • Publication
    Analysis on Behavior Grounding Electrode Resistance base on Profiling Method
    ( 2020-07-09)
    Hashim N.H.
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    Halim N.H.
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    Ariffen A.M.
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    Anuar A.
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    Aqilah Sofiyah Hasni N.
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    Abu Bakar O.
    An earthing system or known as grounding system in an electrical installation where by the grounding system connects specific parts of that installation with the Earth's conductive surface for safety and functional purposes. It is the process of transferring the immediate discharge with the aid of the low resistance wire of the electrical energy directly to the earth. It is really an important role playing in electrical system part as grounding system give protection during fault or lightning occur. In addition, grounding system also give protection for human electrical appliance and building from electrical shocks due to electrical fault or lighting occur. In this research will shows that to identify the best location to install the grounding electrode. This method is used on 10 x 10 meters which is 121 point will be investigated. The result of 0.3m, 0.6m, and 0.9m were analyzed using MATLAB software to produce profiling and shows the perfect location to install the Grounding system electrode.
  • Publication
    Simulation of differential relay for transformer protection
    In electric power system, transformers are an important element and their protection are critical. As the transformer might be damaged during a fault, faster and more selective protection was required. For this purpose, the design of differential protection was utilized. In this study, the differential relay simulation has been successfully done using MATLAB/Simulink. The essential approach is to protect the power transformer against internal faults and avoid interference in the power system. The evaluation has been accomplished at different fault conditions. Several types of faults including double line-to-ground, single line-to-ground and line-to-line faults are studied. Simulation studies were performed and the relays performance with different system parameters and conditions were investigated. The obtained results illustrated for the differential relay represents an appropriate action.
  • Publication
    Prototyping a RF signal-based lightning warning device using with Internet of Things (IOT) integration
    ( 2020-01-07)
    Hwang Y.J.
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    Rohani M.N.K.
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    Mehranzamir K.
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    Ahmad N.A.
    Lightning had caused at least 25, 000 deaths worldwide each year. The study aims to investigate the induced voltage generated by lightning strikes using a lightning detector. Proteus software was employed to simulate the main board of the lightning detector before fabrication. The lightning detector was designed as a radio frequencies receiver and it was tuned to the level (300 kHz to 500 kHz) which enabled it to receive signals from lightning strikes. A lightning simulator was designed using various resistance (100 Ω to 200 Ω) to test the functionality of a lightning detector in order to validate the accuracy of the proposed model. This lightning detector could be activated whenever a small induced voltage (0.2 V and above) were generated by lightning events occurred within 10 km from the detector. This detector captures both the induced voltage and the time difference detected lightning discharge and its sound for further analysis. The time to thunder method was employed to find the estimated lightning discharges distances in parallel to this system in order to validate the current lightning detector. The accuracy of the lightning detector was found to be 88.03%.The analysed data were delivered to the user's smartphone using cloud system.
  • Publication
    Effect of concrete orientation as an enhancement material in grounding system
    To achieve an excellent grounding system, an alternative solution was developed by using enhancement material to modify the soil surrounding the rod. These materials can effectively reduce soil resistivity and grounding resistance for a better grounding system. To achieve this goal, the fundamental part must be taken into account. In this study, the main objective is to analyze different concrete orientations as enhancement material in the grounding system. A 3-D orientation of concrete has been designed using Finite Element Method (FEM) software to analyze the performance of the electric field in the grounding system with different orientation of concrete. Every orientation of concrete had been clarified into four different cases which are full concrete, half concrete, three-quarter concrete, and a quarter concrete. From the result, full concrete is the best orientation of concrete design to be employed at the grounding site as it has a low electric field compared to the other concrete orientation.
  • Publication
    Simulation of reverse power relay in 11 kV generator protection
    ( 2021-05-03) ;
    Lee Y.Y.
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    Nabipour-Afrouzi H.
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    Mousa M.I.
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    Mehranzamir K.
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    This paper proposed the modelling and simulation of generator protection for power system using digital reverse power relay. The operations of the power plant are often interrupted by the reverse power generation. Therefore, generators need to be closely monitored and controlled. In this study, 11 kV synchronous generators are connected to 220 kV load through a step-up transformer, and a new model of reverse power relay is added for generator protection. The reverse power relay proposed in this paper is a digital relay with high accuracy and high reacting speed. Several cases based on various types of mechanical inputs to the generator were studied to test the operation of the reverse power relay. This simulation was done using MATLAB/Simulink. The results show that the 11 kV generator protection is successful with this new model reverse power relay. Besides, the simulation results were similar result compared to the theory result. From the simulation results, the integral output of the relay will reach the threshold value 'L' whenever there is a reversed power flow fault found in the system. Consequently, the relay will be triggered to provide protection for the generator. This model has been added into online resources of MATLAB Power System Tools. In addition, this model may also help the engineers to develop the analytical skills under various conditions.