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Baharuddin Ismail
Preferred name
Baharuddin Ismail
Official Name
Baharuddin, Ismail
Alternative Name
Ismail, Baharuddin Bin
Ismail, Baharudidn
Ismailf, B.
Main Affiliation
Scopus Author ID
24447820000
Researcher ID
GEW-9377-2022
Now showing
1 - 10 of 39
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PublicationHilbert fractal UHF sensor based on partial discharge detection signal for on-line condition monitoring in power transformer( 2020-01-01)
;Roslizan N.D. ;Akashah N.A.Mukhtaruddin A.PD detection is an effective method of inspecting insulation defects and identifying potential faults in a power transformer. Electromagnetic waves generated due to PD can be detected by ultrahigh-frequency (UHF) sensor in the frequency band greater than 300 MHz. However, the size and the frequency bandwidth of a UHF sensor for PD detection are the concern for practical installation inside a transformer. High sensitivity and wide bandwidth of sensors are needed in order to detect the PD signal in an early stage. This paper presents an array 4th order Hilbert fractal UHF sensor for PD detection inside a power transformer. This UHF sensor was modeled to capture PD signal in a range of frequencies between 300 MHz to 3 GHz. The sensor is designed by using CST software where the transmission lines combined 2 sensors become 1 output by setting the dimension of 100 x 200 mm for length and width with FR4 epoxy substrate of thickness 1.6 mm. Based on the simulation result, the proposed sensor is obtained a PD signal measurement with a reflection coefficient below-10 dB with VSWR ≤5. The advantages of this sensor have a wide bandwidth, high sensitivity and suitable size for easy installation. Thus, this sensor has been qualified as UHF PD detection in the power transformer. -
PublicationComparison Study of UHF Sensor Modelling Based on 4th Order Hilbert Fractal Category for Partial Discharge Detection in Power Transformer( 2020-12-11)
;Roslizan N.D.Jalil M.A.A.PD detection is an effective method of inspecting insulation defects and identifying potential faults in a power transformer. Electromagnetic waves generated due to PD can be detected by ultrahigh-frequency (UHF) sensor in the frequency band greater than 300 MHz. However, the size and the frequency bandwidth of a UHF sensor for PD detection are the concern for practical installation inside a transformer. High sensitivity and wide bandwidth of sensors are needed in order to detect the PD signal at an early stage. This paper presents an array with partial ground 4th order Hilbert fractal UHF sensor for PD detection inside a power transformer. This UHF sensor was modeled to capture PD signal in a range of frequencies between 300 MHz to 3 GHz. The sensor is designed by using CST software where the transmission lines combined 2 sensors become 1 output by setting the dimension of 100 x 200 mm for length and width with an FR4 epoxy substrate of thickness 1.6 mm. Based on the simulation result, the proposed sensor is obtained a PD signal measurement with a reflection coefficient below-10 dB with VSWR ?5. The advantages of this sensor have a wide bandwidth, high sensitivity and suitable size for easy installation. Thus, this sensor has been qualified as UHF PD detection in the power transformer. -
PublicationComparative Analysis of 5-level Multilevel Inverter with Reduced Switched Topology( 2022-01-01)
;Arshad M.H.A new topology for the single phase 5-level multilevel inverter is proposed in this paper. Using multiple semiconductor switches and lower-level DC voltages as input, a multilevel inverter generates more than two voltage levels to achieve high efficiency, smoother, and less distorted alternating voltage. The conventional 5-level multilevel inverter requires 8 switches in configurations of two cascaded H-bridge resulting in cost addition as well in generating more losses in the circuit. The proposed topology offers the same 5-level output voltage with lesser power switches resulting in cost-effectiveness as well as improve the circuit complexity. The proposed topology is simulated using PowerSim software to testify its functionality, performance, and validation. A comparative of harmonic distortion between the conventional and the proposed topology is reported. -
PublicationAnalysis of AC voltage and current waveform distortion on SPWM transformerless photovoltaic inverter( 2017-10-01)
;Hermansyah Alam ;Mohd Yusoff Mashor ;Mahrizal MasriButar-Butar A.H.Normally, the low frequency (50Hz) inverter uses a transformer that is bigger in size, heavy and expensive. For reducing the size, weight and manufacturing cost, the SPWM TPVI is suitable, it can generate a sinusoidal AC waveform which is suitable for the long life of AC loads. This paper presents an analysis of AC voltage and current waveform distortion on sinusoidal pulse width modulation (SPWM) transformerless photovoltaic inverter (TPVI). The sinusoidal waveform is developed based on the SPWM technique by installing an LC filter at the end terminal of full bridge inverter. It is due to no optimum value of LC components and AC load, whereas the AC voltage and current waveform will be distorted. Thus, it is very important to analyze the distortion of AC voltage and current waveform. -
PublicationPotential of roselle and blue pea in the dye-sensitized solar cell( 2017-09-26)
;Dayang Suriani ;Gomesh NairThis paper discovers the use of natural dyes from Roselle flower and Blue Pea flower which act as a sensitizer in DSSC and in addition has a potential in absorbing visible light spectrum. The dyes were extracted using distilled water (DI) and ethanol (E) extract solvent in an ultrasonic cleaner for 30 minutes with a frequency of 37 Hz by using 'degas' mode at the temperature of 30°C. Absorption spectra of roselle dye and blue pea dye with different extract solvent were tested using Evolution 201 UV-Vis Spectrophotometer. It was found that Roselle dye absorbs at a range of 400 nm - 620 nm and Blue Pea absorbs at the range of wavelength 500 nm - 680 nm. Fourier-Transform Infrared (FTIR) was used to identify the functional active group in extract dye. The concept of Dye-Sensitized Solar Cell (DSSC) similar to photosynthesis process has attracted much attention since it demonstrates a great potential due to the use of low-cost materials and environmentally friendly sources of technology. -
PublicationMicrogrid synchronization using power offset through a central controller( 2020-01-07)A high penetration of renewable energy in power systems gives rise to the inverter based distributed generators (DG) in the current microgrid system. With the ability of microgrid to operate in both islanded and grid connected mode, a robust and reliable coordination and synchronization between the DGs and the utility grid is crucial to provide a seamless transition between operation modes. Droop based technique is the most popular method in microgrid system, however, voltage or current transient are present during mode transition. A power offset synchronization technique is proposed to provide a seamless transition between modes of operation. The results show that the mode transition is smooth and seamless without any voltage or current transients.
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PublicationElectrical Tree Investigation on Solid Insulation for High Voltage Applications( 2021-01-01)
;Abdulah C.S.K. ;Isa M.A.M.Kamarol M.Electrical treeing is a major cause of a breakdown in solid insulation cable. This phenomenon reduced aging by degrading the insulation, leading to failure in the high voltage materials. The most common experimental set-up in studying the electrical tree is using a needle electrode to initiate the treeing image. Different types of needle and insulation material had been studied from the previous experiment. This paper review the method used to investigate tree growth and its technique to capture the treeing image. Based on this review, several causes delay the treeing process in the needle embedded experiments. In contrast, 2D image processing is the most frequent image developed in the electrical tree on solid insulation. -
PublicationInfluence of PD source and AE sensor distance towards arrival time of propagation wave in power transformer( 2020-01-07)Yii C.C.Partial discharge (PD) often begins with cracks or gas-filled voids in solid insulation or with gaseous bubbles in liquid insulation. These presences can degrade the quality of insulator. PD detection can identify these cracks at high voltage equipment such as power cables and power transformer at the early stage. One of PD detection methods is acoustic emission (AE) detection. PD produces an ultrasonic signal that can be captured by an AE sensor. The signal captured is then analysed by capturing the time of the receiving signal onto the sensor. The information related to time can be used for allocating the PD for maintenance purpose. This paper shows the influence of the distance between PD source and the AE sensor towards the arrival time of propagation wave in power transformer. In this study, the four placements of sensors were analysed by having three possible PD sources to represent the variety of distances between the PD source and the sensor. The simulated signal is generated by MATLAB and the arrival time is captured using time of arrival (TOA) method. The time captured and the distance between the PD source and arrival time showed that the relationship is proportional to one another.
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PublicationMultiple switching pattern for a modified reduce switch multilevel inverter: A comparison analysis( 2020-01-07)Izati Abdullah N.A primary concern of multilevel inverter is its capability to produce desired alternating voltage close to sinusoidal at the output, using multiple sources of DC voltage input. Mostly a multilevel inverter is used to generate the AC voltage from DC voltage. The aim of this paper is to investigate the output of 9 level multilevel inverter by modifying the conventional 5 levels H-bridge cascade multilevel inverter. The proposed design intending to reduce the number of switches from 16 switches to 10 switches. Implementation of different switching pattern methods; equal phase (EP), half equal phase (HEP), half height (HH) and feed forward (FF) and the related expression are presented in this paper. In the result section shows a different percentage of total harmonic distortion achieved. Out of all 4 methods, HH method suppressed distortion wave the most and resulted in the lowest THD in the proposed inverter. This paper shows that by reducing the number of switches in multilevel inverter structure maintains the same quality output as the conventional H-bridge topology. Furthermore, the manipulation of the switches firing angle contribute in decreasing the system THD.