Now showing 1 - 10 of 13
  • Publication
    Development of inductive coil sensor based on Rogowski coil for arcing fault in medium voltage (MV) measurement
    Arcing fault overvoltage is one of the most common problem that always occur in both low voltage (LV) and medium voltage (MV) systems. The arc fault overvoltage in high voltage system is the most dangerous which can easily cause explosion of electrical components such as cable, transformers, switchgears and other equipment. The cause of arc fault overvoltage is due to the loosen cable termination at bus bar and transformers terminal, cable jointing and others. In order to reduce the arc fault risk, the arc circuit interrupter (AFSI) technology and arc fault detectors (AFD) have been developed. However, these devices are more suited for LV or domestic application. For applications in medium voltage (MV), a new arc fault sensor is needed to overcome this problem. Frequent arcing fault overvoltage can cause an interruption of the electrical system which may breakdown the system. Thus, to overcome this matter, the arcing fault sensor was developed in this research. The Rogowski coil (RC) which is one of the inductive coil group was selected as the arc fault detection sensor. Finite Element Method (FEM) was used for electromagnetic flux density, B analysis on RC geometrical and number of turns effect by modelling three different types of RC which are the rectangular, oval and circular cross-section. Based on FEM simulation results, the rectangular cross-section of RC had the highest electromagnetic flux density among the circular and oval cross-section. The mutual inductance calculation of rectangular cross-section has also been performed and compared to the FEM simulation results. There were seven (7) rectangular cross-section RC sensor prototypes that were fabricated using three-dimensional (3D) printer with various number of turns ranging from 20 to 100 with the cross-sectional area ranging between 200 mm2 and 1050 mm2. The acrylonitrile butadiene styrene (ABS) material was selected as the RC sensor core because it has low conductivity, categorized as an insulator, adequate rigidity, good thermal stability, exhibit high toughness even in cold conditions, chemical resistance, environment stress cracking and excellent mechanical properties. The sensor performance verification in terms of sensitivity and bandwidth was conducted with an experimental measurement that was done in the high voltage lab. Based on the experimental results, the RC sensor prototype RC2A5 (fabricated in this research) which has the highest number of turns (100 turns) produced excellent sensitivity at 0.56 kV/mA. However, the bandwidth of RC2A5 descended to 3.51 MHz which is the lowest bandwidth. Whereas, by reducing the number of turns to 20, the RC sensor prototype RC2A1(fabricated in this research) ascended to 7.93 MHz which is the highest bandwidth, but its sensitivity drops rapidly to 0.30 kV / mA. From the obtained results, it can be concluded that that the lower number of turns produced better bandwidth for the RC sensor but reduces the sensor sensitivity significantly. The best RC sensor developed in this work was proposed to be used as an arc fault overvoltage measuring sensor for the future.
  • Publication
    PCB Rogowski coil sensor by using saw blade pattern for arcing fault detection
    (IOP Publishing, 2023)
    Kamarul Aizat Abdul Khalid
    ;
    ; ;
    Zul Hasrizal Bohari
    Rogowski is a special current transformer and has been categorised as a low-power stand-alone current sensor. This sensor is designed by using a Saw blade pattern with 50 turns and 100 turns. This number of turns will impact the increment of the sensitivity of the sensor. Rogowski coil is used for measuring the alternating current (AC) and high-speed current pulses. The PCB Rogowski Coil will detect the arcing fault that design with AutoCAD software after that import to CST software. An arc is created when the electrical current jumps the gap between two conductive materials. The most common causes of arcs include worn contacts in electrical equipment, damage to insulation, break in a cable and loose connections. In order to reduce the arc fault risk, the arc fault interrupter (AFI) technology and arc fault detectors (AFD) have been developed. However, these devices are most suitable for domestic application or low voltage (LV). This paper proposed a simulation using AutoCAD and CST software to design a Rogowski coil and the Rogowski Coil sensor will be tested by using CST software in terms of radiation pattern. The biggest radiation pattern in red colour is the saw blade pattern in 100 turns at 2 KHz frequency, the radiation pattern covering entire sensor area compared with other radiation patterns with other frequency. The main lobe magnitude for 2 KHz frequency is 46.8 dB, main lobe direction is 180 deg, angular width is 153.4 deg and the side lobe level is zero. This is the best number of turn and frequency compared to 50 turn saw blade sensor.
  • Publication
    A review of analysis of partial discharge measurements using coupling capacitor in rotating machine
    (Iran University of Science and Technology, 2025-06) ; ; ;
    Ahmad Syukri Abd Rahman
    ;
    Nur Dini Athirah Gazata
    ;
    Aiman Ismail Mohamed Jamil
    ;
    Mohd Helmy Halim Abdul Majid
    ;
    Normiza Masturina Samsuddin
    Partial discharge (PD) is a critical phenomenon in electrical systems, particularly in high-voltage (HV) equipment like transformers, cables, switchgear, and rotating machines. In rotating machines such as generators and motors, PD is a significant concern as it leads to insulation degradation, potentially resulting in catastrophic failure. Effective and reliable diagnostic techniques are essential for detecting and analyzing PD to ensure the operational safety and longevity of such equipment. Various PD detection methods have been developed, including coupling capacitor (CC), high-frequency current transformer (HFCT), and ultra-high frequency (UHF) techniques, each offering unique advantages in assessing the condition of HV electrical systems. Among these, coupling capacitors have gained significant attention due to their ability to improve the accuracy, sensitivity, and efficiency of PD detection in rotating machines. This study focuses on the advancements in coupling capacitor-based techniques and their critical role in enhancing PD diagnostics for monitoring and maintaining high-voltage rotating machinery.
  • Publication
    Analysis of partial discharge measurements using coupling capacitor in rotating machine
    (Iran University of Science and Technology, 2025-06) ; ; ;
    Ahmad Syukri Abd Rahman
    ;
    Nur Dini Athirah Gazata
    ;
    Aiman Ismail Mohamed Jamil
    ;
    Mohd Helmy Halim Abdul Majid
    ;
    Normiza Masturina Samsuddin
    Partial discharge (PD) is a significant concern in the operation of rotating machines such as generators and motors, as it can lead to insulation degradation over time, reducing the reliability and lifespan of the machines. To monitor PD activity, coupling capacitors (CC) are widely used as sensors for online PD detection, as they can effectively capture PD pulses in high-voltage (HV) rotating machines. The primary objective of this research is to measure and analyze PD signals using a CC sensor for HV rotating machines under varying input voltages and frequencies, following the guidelines of the IEC 60270 standard and utilizing the MPD 600 device. The experimental setup includes performing insulation resistance (IR) testing, PD calibration, and PD measurement. Additionally, this paper provides a detailed study of PD signal characteristics, specifically focusing on phase-resolved partial discharge (PRPD) patterns, to understand the behavior of PD in HV rotating machines, enhancing fault diagnosis and preventive maintenance strategies.
  • Publication
    Application of D-STATCOM to mitigate high inrush current during start-up of three-phase induction motor
    This thesis presents the application of Distribution Static Compensator (D-STATCOM) to mitigate inrush current during start up three phase induction motor. Three phase induction motor draws high current during starting period and will from 6 to 7 times of the rated current of the motor. The effect of high starting current will cause severe damage to motor itself, especially overheating and making motor life expectancy short. In addition, the high starting current will cause the voltage of the power supply rapid drop and affect other devices’ running in the same power line. The purpose of this thesis is to demonstrate that a D-STATCOM is capable to mitigate inrush starting current during start up induction motor. The controller circuit of D-STATCOM has been simulated by using Power System Computer Aided Design (PSCAD/EMTDC) software. The research methodology of this project is to design D-STATCOM circuit which consists of Voltage Source Converter as a main circuit. The function of this circuit is to convert AC to DC and then invert DC to AC before transmit to the threephase power line. The circuit’s has a capability to absorb and inject the reactive and active of the power system which is to control the magnitude of the VSC output voltage. To compare the capability of the D-STATCOM, a Soft starter is developed. The Soft starter circuit is controlled by six thyristors. There were three methods which can be used such as starting the induction motor with direct start-up, starting the induction motor by connecting with the D-STACOM and starting the induction motor with Soft starter. The starting currents of these three methods were observed up to 30 milliseconds and compared. The analysis result shows that the D-STATCOM had mitigated inrush current during start-up induction motor up to 74% higher compared to direct start-up and 164 Ampere is the highest inrush current recorded while direct startup was 637 Ampere recorded. The D-STATCOM was compared with Soft starter to determine the ability of reducing inrush current during start-up induction motor. The result shows that the D-STATCOM had mitigated of 54.3% higher inrush current compared with Soft starter. Hence, the conclusion of this research is the D-STATCOM has a higher capability to reduce inrush current during start up the induction motor compared with Soft starter.
      1  27
  • Publication
    Electricity generation through microbial fuel cells utilizing leftover rice as food waste
    (Semarak Ilmu Publishing, 2023)
    Ahmad Amirul Fitri Abdul Rashid
    ;
    Mohamad Naim Mohd Nasir
    ;
    Zul Hasrizal Bohari
    ;
    Muhamad Sharil Yahaya
    ;
    Mohamad Fani Sulaima
    ;
    Organic food waste management has been a major issue for the environment, as it poses a significant threat to human health and the ecosystem. Converting this waste into a valuable resource is crucial for sustainable development. In this project, we aim to develop a microbial fuel cell (MFC) using leftover rice as a substrate, which can generate electricity through the electrochemical reactions of microorganisms. The main objectives of this study are to investigate the performance of MFCs under two different conditions: with and without a mediator and catalyst. The experimental results showed that both designs of MFCs achieved optimized outputs, with a minimum of 5V voltage output. This demonstrates the potential of MFCs as a promising alternative renewable energy source. MFCs can be utilized as a sustainable energy source, particularly for rural areas, where access to electricity is limited. Furthermore, large-scale operation of MFCs can significantly reduce food waste, which has a significant impact on health and the environment. By converting food waste into electricity, this technology can help mitigate the negative effects of waste accumulation and contribute to the transition towards a circular economy.
      13  1
  • Publication
    Current Sensor Based on Planar Rogowski Coil
    This paper discusses the design and development of current sensor based on planar Rogowski Coil. A Rogowski coil is a toroid of wire used to measure an alternating current through a cable encircled by the toroid. The aim of this study is to design and develop planar Rogowski as a sensor for current measurement and detection using printed circuit board (PCB). The problem of this project is Rogowski Coil (RC) current sensor has same principle as Current Transformer, but the design is different, especially the RC is developed in PCB. Before starting in development of Rogowski Coil current sensor, a few studies are required to review past research on related topic to develop this project. The winding of Rogowski coil current sensor is design by using design software which is EasyEDA to achieve very good sensitivity for wide bandwidth range of frequency at the lowest cost. Finally, the prototype developed is experimented to get the result. The experimental results are discussed and evaluated regarding the performance of the prototype. The highest induced voltage that detected is 55.3 mV and the lowest induced voltage is 11.1mV. The design of Rogowski sensor is significantly shown the best performance of the current sensor in term of sensitivity and bandwidth.
      4  28
  • Publication
    A Contemporary Review of High Voltage Partial Discharge Detection and Recognition Techniques
    ( 2023-07-01)
    Bohari Z.H.
    ;
    ; ; ; ;
    Nasir M.N.M.
    ;
    Sulaima M.F.
    ;
    Ahmad E.Z.
    This review article provides a summary of the most advanced approaches and advancements in the detection and recognition of high voltage partial discharge (PD). It discusses numerous detecting technologies, such as electrical, acoustic, and optical approaches, as well as their merits and disadvantages. It also discusses current developments in signal processing and pattern recognition algorithms used for PD detection and classification. Lastly, the study covers the challenges and limitations in high voltage PD detection and identification studies, as well as potential future solutions.
      3  31
  • Publication
    Partial discharge detection performance using multi-cylindrical slots antenna with parasitic suppression patch for power transforme
    ( 2022-01-01)
    Bohari Z.H.
    ;
    ; ;
    Soh P.J.
    ;
    ;
    Sulaima M.F.
    This paper focused on analyzing multi-cylindrical slots performance combining with parasitic suppression patch for partial discharge detection. Both proposed slots antenna and conventional monopole are simulated using CST Microwave Studio software before being fabricated and tested with real partial discharge signal. Performance comparison will be focused on scattering parameter, radiation pattern and surface current distribution. Both antennas are subjected to a partial discharge signal from lab scaled power transformer for the field test. Based on the result, the proposed performed better in both simulation and field testing with the dual-frequency operation, with better gain improvement by 14%. For the field test, the proposed antenna generated better detection result with reduced noises by 50%.
      10  31
  • Publication
    The magnetic flux density of various geometries of Rogowski Coil for overvoltage measurements
    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.
      31  7