
Hazlee Azil IlliasUniversity of Malaya | UM · Department of Electrical Engineering
Hazlee Azil Illias
BEng(Electrical Engineering)(Universiti Malaya Malaysia), PhD (Electrical)(Southampton UK)
Actively looking for international collaboration and partnership in research projects, publications and supervision...
About
229
Publications
131,811
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,942
Citations
Introduction
Hazlee Azil Illias received Bachelor's Degree in Electrical Engineering from Universiti Malaya, Malaysia in 2006 and PhD Degree in Electrical Engineering from the University of Southampton, UK in 2011. He is currently a lecturer at the Department of Electrical Engineering, Universiti Malaya, Malaysia. His main research interests include modelling and measurement of partial discharge phenomena in solid dielectric insulation, condition monitoring, insulation system diagnosis and lightning.
Skills and Expertise
Education
January 2008 - June 2011
June 2002 - June 2006
Publications
Publications (229)
With the exponential increase in smart device usage across various domains, flexible and conformal antenna technologies have emerged as transformative solutions, enabling wireless systems in numerous smart applications. However, selecting a suitable flexible and conformal substrate remains challenging because of the intricate characteristics and pe...
This work aims to introduce bio-based nanocomposite as high voltage electrical insulation material by using cellulose nanocrystal (CNC) isolated from filter paper as a filler of polymer matrix, in this case, polyvinyl chloride (PVC). CNC is obtained via acid hydrolysis treatment and incorporated into PVC by using the casting method at different con...
Transformer health analysis using Dissolved Gas Analysis is crucial for diagnosing power transformer faults. This paper proposes an innovative approach to diagnose power transformer faults by integrating machine learning algorithms with Ensemble techniques. The method involves fusing reduced dimensional input features through Principal Component An...
A R T I C L E I N F O Keywords: Load frequency control Zebra optimization algorithm Energy storage system IPFC FACTS Redox flow battery SMES A B S T R A C T The high penetration of Renewable Energy Sources (RESs) in the modern power system poses a challenge to power system stability. This stability is affected by the stochastic, fluctuating output...
The development of advanced electrical insulation materials is crucial for the sustainability and efficiency of electrical systems, particularly in high-voltage applications. This study investigates the influence of cellulose nanocrystal (CNC) nanofillers on the dielectric and electrical performance of epoxy composites, aiming to enhance the durabi...
This paper addresses the challenge of limited data availability of Dissolved Gas Analysis (DGA) in fault diagnosis of power transformers. While various classifiers have been employed for fault classification in prior research, their accuracy depends heavily on balanced and synthetic training data. Although resampling techniques have been implemente...
The recent development of artificial intelligence (AI) has opened new avenues in processing parts per million (ppm) for fault detection through dissolved gas analysis (DGA). According to the latest IEC and IEEE standards, the existing methods are only applicable on single fault occurrence. The paper focuses on the challenge of detecting multiple fa...
Insulations at high voltage (HV), whether in HVAC or HVDC systems, often encounter an unwanted partial discharge (PD) phenomenon. PD poses a potential danger to HV insulation and can eventually lead to equipment failures. Out of all electromagnetic (EM) sensing techniques for PD diagnosis, the ultra-high frequency (UHF) method has gained popularity...
The performance of polymer insulators can be significantly compromised by the presence of contaminants, resulting in damage, structural alterations, and accelerated aging. Hence, this research aimed to investigate the discharge behavior of polymer insulators when exposed to various types of contaminants. Three distinct contaminants, namely fly ash,...
There was an error in the original publication [...]
Ultra-high frequency (UHF) antenna-sensors are becoming popular for non-invasive detection of unwanted electric discharge i.e., partial discharge (PD) in high-voltage (HV) systems. Early PD signals are weak for detection and classification by UHF antenna-sensors. Early PD detection and distinction are crucial to prevent equipment failure. Typically...
Lightning overvoltage causes outages of transmission lines (TLs) in tropical countries. Identifying and analyzing the key factors responsible for tripping the lines can improve the performance of the lines. In this work, the flashover patterns due to direct lightning strikes on 275 kV double circuit TLs and towers in Malaysia was evaluated with Ele...
Partial discharge (PD) in insulating materials is a threatening phenomenon for high voltage (HV) equipment. In PD diagnostics, chipless RFID (CRFID) tags have been rarely used despite their recent popularity in so many other sensing applications. So far, only a handful of works have been attempted where CRFID tags are applied to detect PD signals a...
Effective electricity transmission system is critical to the power system stability at the consumer ends. To ensure an uninterruptible supply, the insulation of the transmission lines must be properly evaluated and coordinated. Research has shown that lightning contributes the largest percentage of outages in tropical countries. This work presents...
In recent decades, flash floods have become more common because of climate change and are considered a substantial risk for many cities worldwide. This catastrophic natural hazard presents a significant threat to critical infrastructure in urban areas, particularly the power distribution system. As modern societies are much more dependent on electr...
In compliance with next-generation high-voltage substations, ultra-high frequency (UHF) planar sensors are becoming more popular than ever for their online features in partial discharge (PD) diagnostics. However, PD signals mixing with different noises still exists as a major challenge for UHF sensors. Especially in open substations, telecommunicat...
Direct lightning strikes on overhead lines and towers causes power system outages. Optimal surge arrester placement is a practical and economical protection technique. From research trends, three types of transmission line arresters are in practice: Non-Gapped Line Arrester (NGLA), Externally Gapped Line Arrester (EGLA) and Multi Chamber Insulator...
This work deals with an investigation of negative corona discharge generated from standing wire particles in air insulation. Eight samples from different particle lengths and diameters were studied to understand the effect of particle geometries on discharge characteristics. The particle was stood artificially on the ground inside parallel plane el...
Monitoring the partial discharge (PD) activity of power equipment insulation is crucial to ensure uninterrupted power system operation. PD occurrence is highly correlated to weakened insulation strength. If PD occurrences are left unchecked, unexpected insulation breakdowns may occur. The comprehensive PD diagnostic process includes the detection,...
Ensuring a stable and efficient transformer operation is a very crucial task nowadays, especially with the integration of modern and sensitive electrical equipment and appliances down the line. However, transformer maloperation still cannot be completely avoided, particularly with the existence of inrush current that possess similar characteristics...
The installation of a corona ring on an insulator string on a transmission line is one of the solutions to reduce the electric field stress surrounding the energised end of the insulator string. However, installing a corona ring with an optimum design to reduce the electric field magnitude on an insulator string is a challenging task. Therefore, in...
The reliability of a power system depends on its ability to handle fluctuations and varying load demands, as uncontrolled frequency deviations can lead to load-shedding and blackouts. Optimally tuned controllers are essential for Load Frequency Control (LFC) applications to efficiently stabilize the power system by minimizing frequency undershoots,...
Harvesting energy from ocean wave is a promising renewable energy source due to its high efficiency, carbon-free, it is not affected by depletion of fossil fuels, and it is replenished constantly. The existing generators used in wave energy harvesting such as linear generator and slider crank mechanism have some limitations, which include lower eff...
Growing environmental concerns due to emission of greenhouse gas from the use of nonrenewable resources can be reduced with the aid of renewable resources, which are considered as an alternative fuel in the absence of fossil fuel in the future. Biomass, one of the renewable resources, is supposed to play an important role in energy sectors because...
In this article, we have performed a comprehensive investigation in the specialty of ultra-high frequency (UHF) printable antennas for partial discharge (PD) diagnostics. Due to the complex characteristics of PD signals in UHF range, selection of printable antenna becomes a major concern for PD diagnostics. The main contribution of this article is...
Compared to a spherical metal particle motion within gas insulation, a wire-type particle could have a standing position on the ground electrode. In this work, a numerical investigation and validation from the experimental data of corona discharge from a small protrusion in air insulation within a uniform field under a dc voltage are performed. Thr...
Insulation fault diagnosis is essential because faulty insulation will lead to the interruption of power delivery. Partial discharge (PD) pattern classification is widely used in insulation diagnosis to identify incipient fault before catastrophic failure occurs. PD classification systems improved significantly due to the emergence of advanced mach...
The aim of this article is to present a review of the development and application of superhydrophobic insulation for outdoor high-voltage applications. The methods of preparing insulation exhibiting superhydrophobic properties to mitigate the pollution problem under high voltages in the outdoors are explored. In addition, the existing evaluation te...
Ultra-wideband (UWB) antenna is proposed as ultra-high frequency (UHF) sensor to detect partial discharge (PD) signals. A defected partial ground plane (DPGP) and a radiating patch of a modified trapezoidal shape are designed to achieve UWB characteristics. Compared to conventional PD sensors, the proposed sensor covers a compact area of 140 × 1 60...
This paper presents an investigation of the impact of lightning back flashover on 275 kV double circuit transmission line in Malaysia. Electromagnetic Transient Program (EMTP) was used to model and simulate the effects of the lightning current magnitude, footing resistance and power frequency angle on the performance of the line. The results obtain...
Wideband antenna is proposed as an ultra-high frequency (UHF) sensor for high voltage equipment in smart grid. First, an antenna is designed in UHF range with wideband characteristics. Next, another antenna is designed from the first one to further improve its sensor applicability. Both antennas offer sufficient levels of realized gain and total ef...
Under a DC stress, a wire particle within gas insulation will exhibit complex motion behaviour, leading to more challenges to detect its existence. Therefore, this work deals with an investigation of corona discharge characteristics generated from a wire particle with different particle positions in an air gap. Three different wire particles are pr...
For binary cycle power plants, the energy of solar may be utilized as a heating source. Malaysia has a tropical climate, which receives 4500 kWh/m 2 of solar irradiation on a daily basis and roughly 12 h of sunshine every day. Thus, the potential of binary power cycle plants in Malaysia by utilizing the energy of solar as a source of heat is very p...
The development of artificial intelligence (AI) based techniques for electricity price forecasting (EPF) provides essential information to electricity market participants and managers because of its greater handling capability of complex input and output relationships. Therefore, this research investigates and analyzes the performance of different...
This study uses natural fibre, which is moisture absorbent, as an innovative and economical filler for insulating oil. Rice husk (RH) is a natural fibre known to have water-absorbing properties and used as a supplementary cementitious material. This research utilises the water-absorbing properties of RH to improve the physicochemical and dielectric...
This paper shows a comprehensive comparison study between Nano components and Micro components for high voltage power lines insulation depends on polymers such as Polyethylene like Low-Density Polyethylene (LDPE) and Cross-Linked Polyethylene (XLPE). Potential incidence may happen in the power cable, which is space charge phenomena, increase in the...
This study aims to analyse the effect of natural fibres on the breakdown strength and stability of natural ester as liquid insulating material. Breakdown voltage test is performed to determine the breakdown strength of natural esters. In contrast, the stability of natural esters after the incorporation of natural fibre is determined by comparing th...
In power system networks, automatic fault diagnosis techniques of switchgears with high accuracy and less time consuming are important. In this work, classification of abnormal location in switchgears is proposed using hybrid gravitational search algorithm (GSA)-artificial intelligence (AI) techniques. The measurement data were obtained from ultras...
New and emerging demand for polyurethane (PU) continues to rise over the years. The harmful isocyanate binding agents and their integrated PU products are at the height of environmental concerns, in particular PU (macro and micro) pollution and their degradation problems. Non‐isocyanate poly(hydroxy urethane)s (NIPUs) are sustainable and green alte...
Cellulose and its forms are widely used in biomedical applications due to their biocompatibility, biodegradability and lack of cytotoxicity. It provides ample opportunities for the functionalization of supported magnetic nanohybrids (CSMNs). Because of the abundance of surface hydroxyl groups, they are surface tunable in either homogeneous or heter...
- Partial discharge (PD) pattern recognition is essential since it can help to identify the nature of the insulation defect. Numerous machine learning models have been utilized for PD classification applications in the past. However, traditional machine learning models rely on manual feature extraction to obtain training data. They are usually trai...
Integration between supplies for stationary power and vehicles is potentially useful for increasing the efficiency and the reliability of energy generation systems. Solid oxide fuel cell is one matured technology, which is suitable for a polygeneration system and provides an integration of supply for stationary power and vehicles. However, a combin...
A surge arrester on transmission line is used to deflect lightning surge to ground, avoiding power systems from destruction. During normal condition, there is a leakage current flow through surge arresters where it is one of the main causes of surge arrester humiliation. Thus, monitoring the surge arrester condition is very significant. In this wor...
Cellulose with ample hydroxyl groups is considered as a promising supportive biopolymer for fabricating cellulose supported promising magnetic sorbents (CMS) for magnetic solid-phase extraction (MSPE). The easy recovery via external magnetic field, and recyclability of CMS, associated with different types and surface modifications of cellulose has...
Isocyanate-free composite coating can improve radiative cooling, energy storage and harvesting applications. This study reports the development and use of a isocyanate-free green surface coating(GSC) matrix derived from (2,2,6,6-tetramethylpiperidin-1-yl)oxy radical (TEMPO)-oxidized cellulose-(3-Aminopropyl)trimethoxysilane (APTMS)-ZnO nanoparticle...
Modern societies these days are more dependent on electrical energy and they expect a continuous supply as per
demand. In this regard, the complex power system is designed to supply electrical energy with a certain level of quality and
continuity though it is still susceptible to vandalism, natural disasters, and extreme weather. The black sky even...
Abstract Effective grounding is the most important aspect in every electrical installation because it can ensure efficient equipment operation in the event of electrical faults. Measurement data of soil resistivity is used to assess the suitability of the soil for grounding purpose and also to evaluate the structures of the soil. However, the limit...
Recent studies have proven that a three-coil wireless power transfer (WPT) design shows better performance and has higher efficiency compared to the two coil designs, especially when the source resistance and transmission distance between the primary and receiver coil increases. Three-coil WPT system, similar to two-coil system, is capable of achie...
Hybrid bionanocomposite coating systems (HBCSs) are green polymer materials consisting of an interface between a coating matrix and nanoparticles. The coating matrix was prepared by using a nonisocyanate poly(hydroxyl urethane) (NIPHU) prepolymer crosslinked via 1,3-diaminopropane and epoxidized Jatropha curcas oil. TEMPO-oxidized cellulose nanopar...
Dissolved gas analysis (DGA) is commonly used to identify the fault type in power transformers. However, the available DGA methods have certain limitations because every method depends on the concentration of the dissolved gases. Therefore, in this work, hybrid feature selection–artificial intelligence–gravitational search algorithm (GSA) technique...