Statistical Analysis of Electrical Tree Inception Voltage, Breakdown Voltage and Tree Breakdown Time Data of Unsaturated Polyester Resin

Ahmad, Mohd Hafizi,Bashir, Nouruddeen,Ahmad, Hussein,Piah, Mohamed Afendi Mohamed,Abdul-Malek, Zulkurnain,Yusof, Fadhilah The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

This paper presents a statistical approach to analyze electrical tree inception voltage, electrical tree breakdown voltage and tree breakdown time of unsaturated polyester resin subjected to AC voltage. The aim of this work was to show that Weibull and lognormal distribution may not be the most suitable distributions for analysis of electrical treeing data. In this paper, an investigation of statistical distributions of electrical tree inception voltage, electrical tree breakdown voltage and breakdown time data was performed on 108 leaf-like specimen samples. Revelations from the test results showed that Johnson SB distribution is the best fit for electrical tree inception voltage and tree breakdown time data while electrical tree breakdown voltage data is best suited with Wakeby distribution. The fitting step was performed by means of Anderson-Darling (AD) Goodness-of-fit test (GOF). Based on the fitting results of tree inception voltage, tree breakdown time and tree breakdown voltage data, Johnson SB and Wakeby exhibit the lowest error value respectively compared to Weibull and lognormal.

Statistical Analysis of Electrical Tree Inception Voltage, Breakdown Voltage and Tree Breakdown Time Data of Unsaturated Polyester Resin

Mohd Hafizi Ahmad,Nouruddeen Bashir,Hussein Ahmad,Mohamed Afendi Mohamed Piah,Zulkurnain Abdul-Malek,Fadhilah Yusof 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

This paper presents a statistical approach to analyze electrical tree inception voltage, electrical tree breakdown voltage and tree breakdown time of unsaturated polyester resin subjected to AC voltage. The aim of this work was to show that Weibull and lognormal distribution may not be the most suitable distributions for analysis of electrical treeing data. In this paper, an investigation of statistical distributions of electrical tree inception voltage, electrical tree breakdown voltage and breakdown time data was performed on 108 leaf-like specimen samples. Revelations from the test results showed that Johnson SB distribution is the best fit for electrical tree inception voltage and tree breakdown time data while electrical tree breakdown voltage data is best suited with Wakeby distribution. The fitting step was performed by means of Anderson-Darling (AD) Goodness-of-fit test (GOF). Based on the fitting results of tree inception voltage, tree breakdown time and tree breakdown voltage data, Johnson SB and Wakeby exhibit the lowest error value respectively compared to Weibull and lognormal.

Partial Discharge Characteristics in LLDPE-Natural Rubber Blends

Aulia,Mohd Hafizi Ahmad,Zulkurnain Abdul-Malek,Yanuar Z. Arief,Kwan Yiew Lau,Novizon 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Partial discharges (PD) lead to the degradation of high voltage cables and accessories. PD activities occur due to the existence of impurities, voids, contaminants, defects and protrusions during the manufacture and installation of power cables. Commonly, insulation failures occur at cable joints and terminations, caused by inhomogeneous electric field distributions. In this work, a blend of natural rubber (NR) and linear low density polyethylene (LLDPE) was investigated, and the optimal formulation of the blend that could resist PD was discussed. The experiments were conducted under a constant high voltage stress test of 6.5 kV AC and the magnitude of partial discharge activities was recorded using the CIGRE method II. Pattern analysis of PD signals was performed along with the interpretation of morphological changes. The results showed that the addition of 10 wt% of NR and 5 wt% of Alumina Trihydrate (ATH) provided promising results in resisting PD activities. However, as the NR content increased, more micropores existed, thus resulting in increased PD activities within the samples.

Partial Discharge Characteristics in LLDPE-Natural Rubber Blends: Correlating Electrical Quantities with Surface Degradation

Aulia, Aulia,Ahmad, Mohd Hafizi,Abdul-Malek, Zulkurnain,Arief, Yanuar Z.,Lau, KwanYiew,Novizon, Novizon The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Partial discharges (PD) lead to the degradation of high voltage cables and accessories. PD activities occur due to the existence of impurities, voids, contaminants, defects and protrusions during the manufacture and installation of power cables. Commonly, insulation failures occur at cable joints and terminations, caused by inhomogeneous electric field distributions. In this work, a blend of natural rubber (NR) and linear low density polyethylene (LLDPE) was investigated, and the optimal formulation of the blend that could resist PD was discussed. The experiments were conducted under a constant high voltage stress test of 6.5 kV AC and the magnitude of partial discharge activities was recorded using the CIGRE method II. Pattern analysis of PD signals was performed along with the interpretation of morphological changes. The results showed that the addition of 10 wt% of NR and 5 wt% of Alumina Trihydrate (ATH) provided promising results in resisting PD activities. However, as the NR content increased, more micropores existed, thus resulting in increased PD activities within the samples.

Factor Related to Operational of Marina in West Coast Peninsular Malaysia

Syahmi Firdaus ZAMRI,Ahmad Faizal AHMAD FUAD,Mohd Hafizi SAID 국제이네비해양경제학회 2020 International Journal of e-Navigation and Maritime Vol.15 No.1

Marina is a small port located along a coastline that provides facilities and services for small boats and yachts. The main facilities of marina are pontoon, freshwater, and power supplies. Marina also provides service for boat maintenance and service, and security. In Malaysia, the marina is operated by private companies and Marine Department Malaysia. All the marinas in Malaysia provide the same facilities and services, however they are not operating at the same level. Few marinas had closed their operation due to insufficient number of boats arrived to their marina. The reason of this issue is lack of study about marina operation and management in Malaysia. Further study should be done in this field to overcome this issue and increased the growth of economy for marina. Therefore, the objective of this study to determine the factors to establish a marina in Malaysia and to identify the reason certain marina less performed. This research focused on the marina operators on the west coast of Peninsular Malaysia. The literature review was used to identify the factors to establish a marina. The Analytic Hierarchy Process (AHP) approach was used to analyse the data. This method had ranked the crucial factors from the highest to the lowest percentage. Four main criteria to establish a marina had been identified, namely locations, facilities, services, and promotion. Besides that, there also the sub-criteria for all the main factor to describe it. All the identified factors had been analysed to find the most important factor. The consolidate result showed that geography, security, berthing, purpose, boat chandlery and boat service are the highest percentage among other factors. It concludes that it is the most important factor to establish a marina. These results can be used to improve the operation of marina in Malaysia by focusing on these aforementioned factors.

Effect of Surfactant on Breakdown Strength Performance of Transformer Oil-Based Nanofluids

Zainuddin Nawawi,Muhammad Faris Baharuddin,Izzah Hazirah Zakaria,Mohd Hafizi Ahmad,Aulia,Muhammad Abu Bakar Sidik,Muhammad Irfan Jambak 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

Many approaches to improve the transformer oil characteristics have been made by adding nanofillers into the liquids, but it has caused the existence of sedimentation and agglomeration thereby resulting in incompatibility of transformer oil. In view of foregoing, this paper aims to study the impact of cetyl trimethyl ammonium bromide (CTAB) surfactant added with the nanofiller in improving the compatibility and agglomeration issues towards improvement of breakdown voltage (BDV) characteristics of oil nanofluids. This study was carried out by implementing three different percentages of silica (SiO2) and alumina (Al2O3) nanofillers along with CTAB as surfactant into the mineral oil. The breakdown voltage test was carried out accordance to IEC 60156 standard. The results show that the inclusion of 0.1 wt% SiO2 and 0.1 wt% Al2O3 nanoparticles into mineral oil have improved the BDV. Meanwhile, Al2O3 nanofluids with 0.075 wt% CTAB had good impact on BDV but not on SiO2. This case has reverse behavior with the sedimentation which 0.1 wt% CTAB in SiO2 nanofluids has a good response but not the whole in Al2O3 nanofluids. This could be mainly due to the limitation stability of the nanofluids.