Afifah Shuhada Rosmi
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Afifah Shuhada Rosmi
Official Name
Afifah Shuhada, Rosmi
Alternative Name
Rosmi, Afifah Shuhada
Rosmi, Afifah Shuhada C
Rosmi, A. S.
Rosmi, A. S.C.
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Scopus Author ID
57193830914
Researcher ID
DNN-7471-2022

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  • Publication
    Multiple Partial Discharge Signal Classification Using Artificial Neural Network Technique in XLPE Power Cable
    ( 2023-02-01)
    Halim M.I.A.
    ;
    Razaly N.Z.M.
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Norfadilah Rosle
    ;
    Auni W.N.
    ;
    Afifah Shuhada Rosmi
    ;
    Muhammad Zaid Aihsan
    ;
    Mohd Aminudin Jamlos
    ;
    Mas’ud A.A.
    According to partial discharge (PD) damage in the electrodes that are not entirely bridging, the presence of PD in the high voltage (HV) power cable might lead to insulation failure. PD defects can damage cross-linked polyethylene (XLPE) cables directly, which is one of the most critical electrical issues in the industry. Poor workmanship during cable jointing, aging, or exposure to the surrounding environment is the most common cause of PD in HV cable systems. As a result, the location of the PD signals that occur cannot be classified without identifying the multiple PD signals present in the cable system. In this study, the artificial neural network (ANN) based feedforward back propagation classification technique is used as a diagnostic tool thru MATLAB software in which the PD signal was approached to determine the accuracy of the location PD signal. In addition, statistical feature extraction was added to compare the accuracy of classification with the standard method. The three-point technique is also an approach used to locate PD signals in a single line 11 kV XLPE underground power cable. The results show that the statistical feature extraction had been successful classify the PD signal location with the accuracy of 80% compared to without statistical feature extraction. The distance between PD signals and the PD source affected the result of the three-point technique which proved that a lower error means a near distance between them.
  • Publication
    Review of Edge-based Image Segmentation on Electrical Tree Classification in Cross-linked Polyethylene (XLPE) Insulation
    ( 2021-06-11)
    Mohd Annuar Mohd Isa
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Baharuddin Ismail
    ;
    Afifah Shuhada Rosmi
    ;
    Isa M.
    ;
    Wan Azani Wan Mustafa
    ;
    Kamarol M.
    ;
    Mansor N.S.
    ;
    Nazar N.S.M.
    Electrical trees are the degradation events most linked with partial discharge (PD) activity in cross-linked polyethylene (XLPE) insulation of high voltage (HV) cables. To investigate tree structures and forms, study of electrical tree structures for morphological analysis often carried out using optical microscopy. However, since the noise induced by the occlusion and illumination, as well as by non-uniform intensity either from optical device's setting or the non-standard readout procedure, causes the deterioration of the original microscopy images, resulting in critically loses of information pertaining the tree structures making it difficult to obtained accurate measurement. Image segmentation is one of the potential solutions as it is well-suited for extracting information or certain features from microscopy images. This paper provides review of several segmentation techniques applied on the classification of electrical tree image acquired through lab environment. The works can be separated into three stages. The first step includes the preparation of samples and collection of treeing images by means of real-time microscopy observations. The captured data would then be pre-processed to achieve image binarization. In the next step, image segmentation process is conducted using existing edge-based segmentation methods including Prewitt, Roberts, Canny and Kirsch's templates. Later, comparative analysis will be performed using IQA (image quality assessment) metrics of accuracy, sensitivity, specificity, false-positive-rate and the Matthews Correlation Coefficient (MCC) as the final step. Performance-wise indicates that Kirsch's template able to segment most of the treeing pixels with accuracy of 97.63%, 63% sensitivity, 98.18% specificity and 0.46 MCC while showing low pixels misclassification. This result provides better justification for the integration of the edge-based technique in developing image segmentation algorithm well-matched for the electrical tree analysis in the future.
  • Publication
    Investigation on partial discharge activities in cross-linked polyethene power cable using finite element analysis
    ( 2020-01-07)
    Isa M.A.M.
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Afifah Shuhada Rosmi
    ;
    Muzamir Isa
    ;
    Rosle N.
    ;
    Wan Azani Wan Mustafa
    ;
    Daniel I.N.
    ;
    Roslan M.A.
    The nationwide usage of cross-linked polyethylene (XLPE) for medium to high voltage distribution networks are practically common due to its excellent electrical, thermal and mechanical properties and widely installed through existing network of cable line in Malaysia. However, cable exposures to harsh climates coupled with inadvertent damage throughout installation or transportation are influencing the presence of voids inside the insulation leading to the initiation of partial discharges (PD) in the cable line. Therefore, this study is important to investigate the activities of PD due to the manifestation of voids in XLPE cable and how it affects the physical, electrical and mechanical characteristics of the cable. Analysis has been performed using Finite Element Analysis (FEA) tool to simulate the PD activities in a 2D model of a three (3) core-XLPE insulated armoured sheathed cable (500 mm2, 11 kV) with several placements of voids. The varied placement and radius of voids is very crucial in order to achieve comprehensive analysis. From the obtained result, it has been established that closest the void to the core yielded higher electric field potential. Additionally, it is verified from the simulation that the larger the size of void, the higher the electric field potential consequently increasing the current density inside the void. This simulation and analysis is quite important to provide better insight pertaining to the behaviour of PD in correspond to the presence of voids which will accelerate ageing failure in insulation framework of the XLPE cable.
      20  1
  • Publication
    Electrical Tree Image Segmentation Using Hybrid Multi Scale Line Tracking Algorithm
    ( 2023-01-01)
    Mohd Annuar Mohd Isa
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Baharuddin Ismail
    ;
    Jamil M.K.
    ;
    Muzamir Isa
    ;
    Afifah Shuhada Rosmi
    ;
    Mohd Aminudin Jamlos
    ;
    Wan Azani Wan Mustafa
    ;
    Nurulbariah Idris
    ;
    Mas’ud A.A.
    Electrical trees are an aging mechanism most associated with partial discharge (PD) activities in crosslinked polyethylene (XLPE) insulation of high-voltage (HV) cables. Characterization of electrical tree structures gained considerable attention from researchers since a deep understanding of the tree morphology is required to develop new insulation material. Two-dimensional (2D) optical microscopy is primarily used to examine tree structures and propagation shapes with image segmentation methods. However, since electrical trees can emerge in different shapes such as bush-type or branch-type, treeing images are complicated to segment due to manifestation of convoluted tree branches, leading to a high misclassification rate during segmentation. Therefore, this study proposed a new method for segmenting 2D electrical tree images based on the multi-scale line tracking algorithm (MSLTA) by integrating batch processing method. The proposed method, h-MSLTA aims to provide accurate segmentation of electrical tree images obtained over a period of tree propagation observation under optical microscopy. The initial phase involves XLPE sample preparation and treeing image acquisition under real-time microscopy observation. The treeing images are then sampled and binarized in pre-processing. In the next phase, segmentation of tree structures is performed using the h-MSLTA by utilizing batch processing in multiple instances of treeing duration. Finally, the comparative investigation has been conducted using standard performance assessment metrics, including accuracy, sensitivity, specificity, Dice coefficient and Matthew’s correlation coefficient (MCC). Based on segmentation performance evaluation against several established segmentation methods, h-MSLTA achieved better results of 95.43% accuracy, 97.28% specificity, 69.43% sensitivity rate with 23.38% and 24.16% average improvement in Dice coefficient and MCC score respectively over the original algorithm. In addition, h-MSLTA produced accurate measurement results of global tree parameters of length and width in comparison with the ground truth image. These results indicated that the proposed method had a solid performance in terms of segmenting electrical tree branches in 2D treeing images compared to other established techniques.
      1  26
  • Publication
    A Potential Controller for Smart Electrical Energy Management System
    ( 2021-06-11)
    Kumuthawathe Ananda-Rao
    ;
    Mohd Alif Ismail
    ;
    Afifah Shuhada Rosmi
    ;
    Leow Wai Zhe
    ;
    Surina Mat Suboh
    ;
    Muhammad Izuan Fahmi Romli
    ;
    Abdullah A.M.
    Integrated energy utilization has been recognized as a productive way towards better energy management, besides increasing Renewable Energy (RE) penetration. Thus, the combination of RE integrated with the Battery Energy Storage System (BESS) has been recognized as the primary solution where it is necessary to have a controller to interface the system efficiently. Hence, a smart electrical energy management system controller is designed and developed based on load leveling and peak shaving applications for real-time AC power management in this work. The main function of the controller is to continuously monitor and maintain the load demand and to produce a leveled or shaved load profile that will be seen at the grid network by controlling the battery operation. The testing results concluded that the controller able to perform both the energy applications. Overall, a dual function controller based on energy applications to maintain consumer load demand usage more securely and reliably, so that the utility bill is reduced and the battery lifetime is prolonged simultaneously is achieved in this work.
      9  28
  • Publication
    The magnetic flux density of various geometries of Rogowski Coil for overvoltage measurements
    ( 2020-01-01)
    Ayob Nazmy Nanyan
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Muzamir Isa
    ;
    Afifah Shuhada Rosmi
    ;
    Ahmad Zaidi Abdullah
    ;
    Baharuddin Ismail
    ;
    Haziah Abdul Hamid
    Overvoltage phenomenon is the common problem that always occurs in the power system and can cause the electrical system network breakdown, and in some cases, it may explode. The frequent overvoltage also can affect and degrade the lifespan of the electrical power system components and network. Thus, the overvoltage sensor is needed to overcome this problem matter. The Rogowski coil (RC) is one of an inductive coil group, and it is suitable for measuring the alternating current (AC) and transient currents or overvoltage. This paper demonstrated the effect of RC magnetic flux density, B with difference cross-section, geometries sizing and the number of turns by using Finite Element Method (FEM). Commonly, there are three types of RC widely used; rectangular, circular and oval. Each of these cross-sections has different characteristics in term of performance. The results have shown that the rectangular cross-section is better than oval and circular cross-section based on the number of magnetic flux density.
      29  7
  • Publication
    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.
      1  30
  • Publication
    UHF Sensors for On-line Partial Discharge Detection on Power Transformer: Hilbert fractal, Moore Fractal and Peano fractal
    ( 2020-12-11)
    Alleef Abd Jalil, Muhammad
    ;
    Afifah Shuhada Rosmi
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Muzamir Isa
    ;
    Roslizan N.D.
    ;
    Leow Wai Zhe
    ;
    Mohd Aminudin Jamlos
    Partial discharge (PD) is the causes of the fault to occur in high voltage equipment due to the breakdown of the insulation system happen on equipment, even old equipment or new equipment. The PD in transformer oil is one of the significant causes of insulation failure and a breakdown. Hence, a sensor is needed to continuously monitor and detect the PD at an early stage on the power transformer. An antenna is one of the sensors that can be used to detect PD based on ultra-high frequency (UHF) method. However, the size of the antenna is the main problem to be installed in the transformer tank. Thus, three types of antenna which are Moore, Hilbert and Peano fractal with the dimension of 10 X 10 cm is designed to operate in UHF range 0.3 GHz to 3 GHz to be able to detect the frequency of partial discharge signal generated by electromagnetic waves. The performance of the proposed antennas in terms of return loss, Voltage Standing Wave Ratio (VSWR) and radiation pattern are analysed and compared for PD detection on the power transformer. Based on the result, the fourth-order of Hilbert fractal antenna was found to be the best antenna for PD detection in power transformer at working frequency range from 0.72 GHz to 2.77 GHz. This antenna also has low threshold of return loss at-36.2 dB for the resonant frequency at 1.67 GHz and the value of VSWR is near to one which is 1.03. Lastly, the radiation pattern of this antenna is almost in hemisphere shape and the gain variation of all frequencies are nearly stable compared to the other types of antenna.
      7  23
  • Publication
    Electrical Tree Investigation on Solid Insulation for High Voltage Applications
    ( 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
    ;
    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.
      8  32
  • Publication
    Development and Performance Analysis of the Rogowski coil sensor for Arcing Fault Measurement
    ( 2020-03-20)
    Ayob Nazmy Nanyan
    ;
    Muzamir Isa
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Haziah Abdul Hamid
    ;
    Afifah Shuhada Rosmi
    ;
    Mardianaliza Othman
    ;
    Ahmad Zaidi Abdullah
    ;
    Zamri Che Mat Kasa
    ;
    Ami Nurul Nazifah Abdullah
    Arcing fault is an overvoltage that usually occurs in the power system network, and it is necessary to monitor this phenomenon in electrical equipment. This paper presents the Rogowski coil (RC) as an arcing fault sensor. Finite element method (FEM) software used for analysing the RC magnetic flux density with two types of RC with the different turns and size demonstrated. The sizing of RC based on the 240 mm2 cross-link polyethene (XLPE) 11 kV underground cable. The prototypes of the RC sensors were designed using Solidworks software and three-dimensional (3D) printer for fabrication purposes. The main objective of the experiment is to investigate the RC effect with high magnetic flux density by implementing in real measurement. An experimental setup for real arcing fault with various voltages (up to 15 kV) was conducted to verify the RC performance, such as sensitivity and bandwidth range. The result has shown that the bandwidth of RC 1 is higher than RC 2 in all measurement by 22.6%.
      2  50