Baharuddin Ismail
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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

Research Output

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Comparison of Image Restoration using Median, Wiener, and Gaussian Filtering Techniques based on Electrical Tree

2021-01-01 , Abdulah C.S.K. , Mohamad Nur Khairul Hafizi Rohani , Baharuddin Ismail , Isa M.A.M. , Afifah Shuhada Rosmi , Wan Azani Wan Mustafa

Electrical treeing lead to a major cause of a breakdown in solid insulation. Thus reduced solid insulation performance by degrading the insulation. Hence, it is important to study the electrical treeing and learn the root cause of the treeing formation. In this paper, the performances of median, wiener, and gaussian filters in restoring noisy images are studied based on electrical tree images. The electrical tree colour images is being transform into grayscale images, noisy images using impulse noise (salt and pepper), and finally motion blur are applied. Even though, there are several number of filters available, this paper focus on median, wiener, gaussian, and combination of the filters. In the end, comparison between these filters is made to study the efficiency using PSNR, SNR, and MSE in graph form.

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Influence of PD source and AE sensor distance towards arrival time of propagation wave in power transformer

2020-01-07 , Khairul Nadiah Khalid , Mohamad Nur Khairul Hafizi Rohani , Baharuddin Ismail , Muzamir Isa , Afifah Shuhada Rosmi , Wooi Chin Leong , 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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The effect of amplitude modulation index on harmonic distortion in unipolar SHEPWM inverter

2021-12-01 , Norhanisa Kimpol , Ahmad Muhyiddin Yusof , Muhammad Zaid Aihsan , Baharuddin Ismail , Mohd Hafiz Arshad , Mohd Saifizi Saidon

The appearance of low order odd harmonic in the AC power line can be mitigated by projecting a proper switching angle during the conversion of the inverter. The switching angles can be obtained by solving the numerical nonlinear equation using numerous solving techniques and algorithms. Several studies shows the value of harmonic significantly increase whenever the amplitude modulation decrease for the SPWM switching scheme of the inverter. However, this topic has not yet covered in the single-phase SHEPWM inverter. This paper is to study the effect of the amplitude modulation index towards the harmonic distortion in the SHEPWM switching technique. To solve the numerical equations, MATLAB code is used to produce the specific switching angles to drive the inverter by solving the numerical equations. The validation of results thru hardware implementation using EZDSPTMS320F28335 to produce the digital signal for controlling the inverter. The targeted low order harmonic to be eliminated are the 3rd, 5th and 7th and three four amplitude modulation indices will be compared and observed in term of total harmonic distortion. The THD results for amplitude modulations 0.6, 0.7, 0.8 and 0.9 are 17.50%, 15.10%, 13.30% and 10.63%.

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A review: Partial discharge detection using acoustic sensor on high voltage transformer

2020-01-07 , Akashah N.A. , Mohamad Nur Khairul Hafizi Rohani , Afifah Shuhada Rosmi , Muzamir Isa , Norfadilah Rosle , Baharuddin Ismail , Wooi Chin Leong

Partial discharge (PD) is an electrical discharge which is one of the most critical breakdown factor that is affecting the electrical equipment. The loss of the power will affect consumers and system operation. High voltage (HV) transformer is one of the equipment's subjected to phenomena PD. In this paper reviews an application of acoustic methods in transformer and piezoelectric sensors application on PD detection in HV transformer. Based on this review, the new design in acoustic sensor is required in order to improve the sensitivity and bandwidth for PD detection at HV transformer. The valuable parameter such as materials, size, and PD frequency range were discussed in this paper and can be used for early stage on designing new acoustic sensor. This detection method given some benefits on preventing the power electrical system from breakdown.

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Protection Relay Setting based on Overcurrent Phenomena in Commercial Building

2024-03-01 , Isyraq Faizzi Mohammad , Mohamad Nur Khairul Hafizi Rohani , Afifah Shuhada Rosmi , Baharuddin Ismail , Muhamad Hatta Hussain , Abdullahi Abubakar Mas’ud , Firdaus Muhammad-Sukki

Nowadays, every single distribution system needs to install an appropriate relay to keep the system safe. The operational and commonly recommended relay for distribution systems is the overcurrent (OC) relay. Throughout the distribution system, the protective relay is one of the methods that can detect and protect the location according to its observation from any fault from abnormal activity. Note that time coordination between the protective equipment relay needs to be a minimum of time interruption to prevent faults occurs. The ideal setting for all coordination protection relays is necessary to protect the device against electrical failure and interference. This paper analyzes the real results data collected for the selected commercial building of an OC relay implemented in a distribution board for high voltage and low voltage downward at a commercial building. All the parameters need to be clarified first before testing has been made and measurement is carried out using the MICROTEST 860 set. Based on the analysis, it proves that according to the IEC Standard of 0.10-time multiplier Setting (TMS) is practical to be used to obtain the operation time in seconds for the current curve set. Other than that, the results show that the normal inverse curve from manual calculation results is more accurate compared to the service setting (SS) made based on the incoming setting in a real commercial building. The case study for OC relay setting is related between current injection and time-tripping, which complies with the IEC 60255-3 standard using its formula. This method was applied to determine the characteristics of the curve. Hence, this research successfully determined the proper methods for the OC relay setting for the power distribution system. Besides, the feasibility and efficiency of OC relay data transmission are tested and checked successfully to implement the measurement method in the relay coordination study.

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Modelling of piezoelectric sensor based on ZnO material for partial discharge detection on power transformer

2020-01-01 , Akashah N.A. , Mohamad Nur Khairul Hafizi Rohani , Afifah Shuhada Rosmi , Muzamir Isa , Baharuddin Ismail , Kamarol M. , Roslizan N.D. , Khairul Nadiah Khalid

Detection of partial discharge (PD) in early stages able to reduce the risk of decommissioning of high voltage (HV) equipment. However, the conventional method for PD detection are not suitable for on-site measurement due to electrical disturbance. One of the method in detecting PD signal is piezoelectric based acoustic emission (AE) sensors. In this project, an AE sensor is modelled to obtain a PD signal in the range of 10 – 300 kHz occurred in HV transformer and been found out by simulation and analytical approach. Two models of a piezoelectric sensor with different types of cantilever and different dimension variation starting from 4 mm to 15 mm are designed in the Finite element Method (FEM) in order to investigate the resonant frequency which is matched to the range of AE detection. Zinc oxide (ZnO) as a piezoelectric material is proposed in this project due to its high piezoelectric coupling and environmentally friendly compared to the others material which is harmful. Based on the simulation result, ZnO piezoelectric sensor with the length of 5 mm and thickness of 0.451 mm generates 0.0537 mV electrical potentials under the resonant frequency of 155.30 kHz which is in the range of AE detection technique.

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Hilbert fractal UHF sensor based on partial discharge detection signal for on-line condition monitoring in power transformer

2020-01-01 , Roslizan N.D. , Mohamad Nur Khairul Hafizi Rohani , Afifah Shuhada Rosmi , Baharuddin Ismail , Muzamir Isa , 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.

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Comparative Analysis of 5-level Multilevel Inverter with Reduced Switched Topology

2022-01-01 , Arshad M.H. , Baharuddin Ismail , Muhammad Zaid Aihsan , Zainuddin Mat Isa , Siti Khodijah Mazalan

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.

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Selective Harmonic Elimination Pulse Width Modulation for Three-Phase Nine-Level Inverter Using Improved Whale Optimization Algorithm

2023-10-06 , Bimazlim M.A.S. , Baharuddin Ismail , Muhammad Zaid Aihsan , Rosnazri Ali , Talib M.H.N. , Muhammad Azhar Walter M.S. , Siti Khodijah Mazalan , Mohamad Nur Khairul Hafizi Rohani

For many years, multilevel inverter (MLI) is a system well-known for converting DC voltage to AC voltage which is suitable for energy resources conversion for industrial power sources. With the help of Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) switching technique, the output power from the MLI system is better efficiency with low Total Harmonics Distortion (THD). The SHEPWM switching technique is used to eliminate the lower order of the harmonics and reduces the Total Harmonics Distortion (THD) of the MLI system. Along with the optimization algorithms to solve difficult non-linear equations involving with SHEPWM, applying SHEPWM into MLI system helps to further improve the output power efficiency. Whale Optimization Algorithm (WOA) is one of the algorithms developed which capable of solving the non-linear equation and obtained suitable results for MLI. Additionally, many types of improvement done on WOA, called as Improved Whale Optimization Algorithms (IWOA) also developed to obtain better results compared with WOA. Developed in a MATLAB environment, a proposed IWOA is applied to solve the equation and compared with WOA. The results show that the proposed IWOA capable of achieving higher probability with fast convergence speed reaching global optimal compared to WOA. With the proposed approach, the IWOA efficiently computed required switching angles, to eliminate the selective lower-order harmonics for different modulation indices (Ma). In this paper, the proposed IWOA is performed on a three-phase nine-level cascaded H-bridge multilevel inverter (CHBMLI) for a wide range of modulation indexes between 0.1 until 1. The results show the eliminations of 5th, 7th, and 11th harmonics from the output of the three-phase nine-level MLI system thus reducing THD from the system up to 5.82%.

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A Review: Partial Discharge Detection using UHF sensor on High Voltage Equipment

2020-01-07 , Roslizan N.D. , Mohamad Nur Khairul Hafizi Rohani , Wooi Chin Leong , Isa M. , Baharuddin Ismail , Afifah Shuhada Rosmi , Wan Azani Wan Mustafa

Partial discharge (PD) is one of the most popular failure or breakdown that can happen at high voltage (HV) equipment. PD is the fault that causes the insulation breakdown occurred between two electrodes. It happened or occurred because of the improper insulation, ageing, environment effect and manufacturing defects. The loss of the power will affect consumer and system operation. One of the technique that can measure or detect the PD is by using ultra high frequency (UHF) method for HV equipment insulation condition monitoring and assessment. In this paper, the application of UHF method have been reviewed as the best method to detect PD in transformer, GIS and cable. The UHF method for every electrical equipment is described in order to detect the PD and the laboratory result shows that this method can be considered as suitable technique. Based on this review, the new design in UHF sensor is required in order to improve the sensitivity and bandwidth for PD detection in HV equipment. The valuable parameter such as size and PD frequency range can be used for early stage of designing new the UHF sensor.

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