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.
Main Affiliation
Scopus Author ID
57193830914
Researcher ID
DNN-7471-2022

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  • Publication
    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.
  • 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.
  • 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
    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.
  • Publication
    Partial discharge signal measurement based on stand-alone and hybrid detection technique for power transformer
    ( 2020-01-01)
    Jalil M.A.A.
    ;
    Afifah Shuhada Rosmi
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Muzamir Isa
    ;
    Auni W.N.
    ;
    Ahmad Zaidi Abdullah
    ;
    Aizam M.T.
    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
    Piezoelectric Sensor using PZT Material for Partial Discharge Detection on Power Transformer
    ( 2020-07-09)
    Alleef Abd Jalil M.
    ;
    Afifah Shuhada Rosmi
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Muzamir Isa
    ;
    Nurul Auni Wan Mohammad W.
    ;
    Zaidi Abdullah A.
    ;
    Wan Azani Wan Mustafa
    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
    Analysis on Multiple Acoustic and Electrical Emission of PD Signal Based on Signal to Noise Ratio (SNR) on Power Cable
    ( 2020-12-11)
    Mohammad W.N.A.W.
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Norfadilah Rosle
    ;
    Khairul Nadiah Khalid
    ;
    Afifah Shuhada Rosmi
    ;
    Ahmad Zaidi Abdullah
    ;
    Jamil M.K.M.
    Acoustic Emission (AE) and Electrical Emission (EE) partial discharge (PD) monitoring are effective methods in detection of the insulation failure in power cables. However, the unwanted noise from the surrounding environment can influence the effectiveness and accuracy of the PD measurement on the PD signal. Therefore, Discrete Wavelet Transform (DWT) denoising technique is introduced in order to suppress the disrupted noise. In this study, a different type of mother wavelet, level decomposition and its frequency spectrum on multiple AE and EE PD signals were performed via MATLAB software in order to analyze the performance of denoising technique. These PD signals were deal with white noise and Discrete spectral interference (DWT). The better performance of denoising technique is based on evaluating the maximum value of Signal to Noise Ratio (SNR) in order to find the optimum mother wavelet. In this case, the most optimum mother wavelets are rbio3.3 for AE and EE PD signals respectively with the highest value of SNR.
      4  21
  • 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.
      6  23
  • 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%.
      6  3