Ahmad Zaidi Abdullah
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Preferred name
Ahmad Zaidi Abdullah
Official Name
Ahmad Zaidi, Abdullah
Alternative Name
Bin Abdullah, Ahmad Zaidi Bin
Abdullah, Ahmad Zaidi Bin
Abdullah, Ahmad Zaidi
Abdullah, A. Z.
Main Affiliation
Scopus Author ID
56878313200
Researcher ID
W-3280-2019

Research Output

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Measurement and Identification of Partial Discharge in 11kV XLPE Cable Jointing

2023-01-01 , Jamalil S.A.S. , Ahmad Zaidi Abdullah , Hamzah M.H. , Bohari Z.H.

The reliability of power networks can be compromised by failures in cable connections, which are often caused by poor insulation quality. The use of different insulating materials during the connection process can result in defects, leading to partial discharge (PD) in high voltage equipment. PD measurements using a Rogowski Coil sensor and a high-efficiency Oscilloscope, following the IEC-60270 guidelines, are a widely recognized method for evaluating the quality of insulation systems. Experimental measurement was performed at university high voltage laboratory. This paper focuses on measuring PDs in extension (joint) cables, where they typically occur, specifically in 11kV XLPE jointing cables, and comparing them with ordinary cables without jointing. The project aims to analyze PD signal characteristics and identify partial discharge patterns in the time and frequency domains using MATLAB.

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Partial discharge detection performance using multi-cylindrical slots antenna with parasitic suppression patch for power transforme

2022-01-01 , Bohari Z.H. , Muzamir Isa , Ahmad Zaidi Abdullah , Soh P.J. , Ayob Nazmy Nanyan , 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%.

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A Simulation Study of Performances for Different Substrates Sizes and Copper Thickness for PD Antenna Design

2020-09-27 , Bohari Z.H. , Muzamir Isa , Soh P.J. , Ahmad Zaidi Abdullah , Ab Rahman A. , Nasir M.N.M.

Partial discharge (PD) is a phenomenon that consistently happens throughout the millennium in the power equipment. This phenomenon has an unpredictable and intermittent characteristic that hard to be detected easily. There are various available methods to detect this phenomenon, but each technique has its own flaws and drawback. This paper explored the early step to select, design, and simulate a PD UHF antenna for power transformer through CST MWS simulation. This task is crucial to choose the optimized substrate size and copper thickness for the PD antenna design. Based on the detailed analysis, it is substantially proven that there is an important relationship between substrate size towards antenna performance and characteristics to design an improved and efficient PD antenna.

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Development of detachable Rogowski Coil current sensor using PCB for High Voltage cable partial discharge measurement

2022-01-01 , Syed Akhmal Syed Jamalil , Muzamir Isa , Ahmad Zaidi Abdullah , Ayob Nazmy Nanyan , Bohari Z.H.

Insulation failure in High Voltage (HV) cables is evaluated using a variety of monitoring techniques. Previous silicon technologies were outperformed by wide-bandgap semiconductor power devices with faster switching speeds. Their precise current management or current protection measures must be upgraded. As a result, their precise current control or protection measures have become more sophisticated. The traditional Rogowski Coil (RC) with the magnetic core, on the other hand, has low measurement accuracy, a short measuring range, and is difficult to fabricate. This paper presents and discusses the development of a Rogowski Coil using a detachable Printed Circuit Board (PCB) as a current sensor for Partial Discharge (PD) measurement. Furthermore, the development of this innovative current sensor concentrated on the detachable PCB Rogowski Coil's capability to measure as a high-voltage (HV) current sensor and its sensitivity in fault diagnosis, over-voltage current sensing, and high-impulse current sensing on HV cables. The experimental design, techniques, and measurement parameters used in models were discussed. Finally, a brief analysis of the detachable PCB RC current sensor such as sensitivity, maximum voltage and current detection is presented. This paper can also be used as a guideline for other researchers to develop an advanced RC current sensor using PCB as a HV current sensor in the future. The measurement results of the detachable PCB RC current sensor such as the sensitivity and current detection signal can also be used as a guideline by another researcher. As a result, the goal of this project is to measure PD on HV cables using an RC current sensor by utilising PCB technology.

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A Contemporary Review of High Voltage Partial Discharge Detection and Recognition Techniques

2023-07-01 , Bohari Z.H. , Muzamir Isa , Faizah Abu Bakar , Ahmad Zaidi Abdullah , Ayob Nazmy Nanyan , 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.

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Dynamic Partial Discharge Characteristic for Onsite Measurement Based on Zero Crossing in Power Cable

2022-01-01 , Ahmad Zaidi Abdullah , Bohari Z.H. , Nurhafiza Azizan , Muzamir Isa

This paper analyzed the dynamic Partial discharge (PD) characteristic for onsite measurement based on zero crossing in high voltage power cable. According to IEC60270, high voltage measurement characteristic is required to identify correct PD signal. There is currently limited research operating on the trait, especially zero crossing, and because of this, comprehensive PD detection characteristics need to be further established in certain severe conditions. This occurrence has an erratic and sporadic characteristic that is challenging to identify. This paper explored the time of zero crossing for onsite measured PD signal for power cable through MATLAB simulation. This task is crucial to choose the range of zero crossing time based on the highest peak of detected PD signal. Based on the detailed analysis, it is substantially identified that there is an specific time only for PD signal with the highest amplitude, and based on detected times, a range of zero crossing characteristic was described for PD signal. It provided a useful analysis result for the guideline during onsite PD measurement for power cable.

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