Azrul Mohd Ariffin

Measurement and simulation of partial discharge activity within a void cavity in a polymeric power cable model

In high voltage power cable, partial discharge (PD) phenomenon may occur within defects that exist in its insulation system. The insulation is normally made of a dielectric material, typically polymeric materials. Repetition of PD activity at the defect site may cause insulation breakdown when the defect grows until it bridges the electrodes between the insulation. Consequently, breakdown of the whole cable will occur. Thus, measurement of PD activity within cable insulation system has been extensively used to monitor the condition of power cables in service. A void cavity is one of the most common PD sources when a cable insulation is stressed under high electric field. In this work, measurements of PD activity within an artificial cylindrical void in the insulation layer of a 22 kV cross-linked polyethylene (XLPE) cable was performed. A two-dimensional model of a cable insulation geometry with a void was also developed using finite element analysis (FEA) software. The model was used to calculate the electric field magnitude in the void within the cable insulation under different conditions of voids and insulation. From this work, an understanding on PD phenomenon within a cylindrical void in a power cable insulation can be enhanced.

Modelling of partial discharge pulses in high voltage cable insulation using finite element analysis software

Measurement of partial discharge (PD) in high voltage equipment is widely used in condition assessment and performance maintenance of the insulation system. One of the methods to evaluate PD data from condition monitoring activities is by analysing PD signals captured from the PD detection equipment. In high voltage power cable, PD pulses originated from defect sites within cable insulation can propagate along the insulation. A better understanding of PD pulse propagation along cable insulation can be attained through simulation work. Therefore, in this paper, the propagation of PD pulses within cable insulation was simulated using finite element analysis (FEA) software and its velocity of propagation was calculated. The result was compared with the theoretical value and simulation results using PSCAD software. The effect of cable insulation parameters on the PD pulse propagation was also studied through the FEA model; these include variation of the permittivity and conductivity of the insulation material.

Electric field distribution in 132 kV XLPE cable termination model from finite element method

High voltage cable terminations are widely used in power system networks. A proper design of cable termination is essential in reducing the electric field distribution around the end of high voltage cable. However, if there are defects exist at cable termination structure, the electric field can be enhanced significantly and can be the source of electrical discharges. Therefore, it is important to understand the effect of defects on the electric field distribution at cable terminations. In this work, a 132 kV XLPE outdoor cable termination has been modelled using finite element analysis (FEA) method. The model has been used to simulate the electric field distribution in the cable termination in the presence of defects. Defects that have been considered are void defect in porcelain, stress cone and fluid, sharp pin on the porcelain surface and delamination defect between the insulator and the stress cone. The effect of different void location, material dielectric constant and porcelain radius on the electric field magnitude at cable termination have also been investigated. From the results obtained in this work, a better understanding of the electric field distribution at the cable termination with defects can be attained.

Electroluminescence measurements of low-density polyethylene (LDPE) films subjected to high electrical stresses in different gas environments

It has been proposed that the measurement of the characteristics of electroluminescence (EL) observed during the application of ac and dc electric fields across thin films of polymeric material can be used to probe the early stages of electrical ageing. Both EL and electrical ageing of the polymer are thought to arise due to the injection of charge carriers into the material from the metallic electrodes. However, before changes in the EL characteristics can be properly assigned to polymeric ageing, it is necessary to understand the physical processes that give rise to EL. In this paper, the effect of absorbed gases N2 and SF6 on the EL characteristics of low density polyethylene were examined. It was found that the EL can be split into two different spectral components, C1, having a broad peak centered at a wavelength between 550 and 600 nm, and a second component, C2, having a peak wavelength greater than 700 nm. The intensity of the C1 component of EL was found to depend on the type absorbed gas present in the material while the intensity of the C2 component was found to be independent. The results demonstrate that the electronegativity of the absorbed gas plays a fundamental role in the formation of excited states and subsequent recombination in the case of the C1 emission while the C2 emission supports the conjecture that this is due to the excitation of surface plasmons at the dielectric/polymer interface.

Development of treeing detection method for cable with three insulation regions using tdr technique

Treeing is a typical factor that contributes to aging of polymeric insulated cables. The occurrence and proliferation of these water trees cause electricity disruptions which interfere with the proper operation of the lines. This has resulted in a strong need for techniques to identify treeing degradation in polymeric insulated cables. In previous studies, a method that uses time domain reflectometry (TDR) technique to detect and locate water tree within two insulation regions has been shown to be feasible. Thus, this paper attempts to investigate on the potential of using the same method on cable with three insulation regions. Cable is modelled using MATLAB simulation tool to obtain the cable impedance for PSpice set-up simulation where the TDR technique is applied. The pulse reflections from the PSpice simulations are recorded and analysed to investigate whether this technique is capable of detecting water tree within three insulation regions.

Electroluminescence of ultraviolet and thermally aged low density polyethylene

It has been postulated that long term ageing of low-density polyethylene (LDPE) is due to the movement of space charge within the dielectric. Electroluminescence (EL) has been shown as an alternative method to investigate charge movement within a dielectric. Under ac fields, EL is related to the injection, trapping and recombination of charge carriers at the sample interface. This work investigates the change in EL emission due to the ultraviolet (UV) ageing of additive free 100µm LDPE films. Samples are aged in an oven using a 36W UV fluorescent tube at a temperature of 313K. This causes bond breakages and increased carbonyl and hydroxyl groups as confirmed by Fourier transform infrared (FTIR) spectroscopy. Weibull breakdown statistics also show an increasing reduction in the ac ramp breakdown strength with ageing time. EL images and temporal measurements are collected using a deep cooled charge coupled device (CCD) camera and show an initial reduction in the EL with ageing. Further ageing shows a field dependence of the EL.

Verification of MATLAB/Simulink Power Cable Modelling with Experimental Analysis

Received Mar 3, 2018 Revised Apr 11, 2018 Accepted Apr 21, 2018 Paintball has gained a huge popularity in Malaysia with growing number of tournaments organized nationwide. Currently, Ideal Pro Event, one of the paintball organizer found difficulties to pair a suitable opponent to against one another in a tournament. This is largely due to the manual matchmaking method that only randomly matches one team with another. Consequently, it is crucial to ensure a balanced tournament bracket where eventual winners and losers not facing one another in the very first round. This study proposes an intelligent matchmaking using Particle Swarm Optimization (PSO) and tournament management system for paintball organizers. PSO is a swarm intelligence algorithm that optimizes problems by gradually improving its current solutions, therefore countenancing the tournament bracket to be continually improved until the best is produced. Indirectly, through the development of the system, it is consider as an intelligence business idea since it able to save time and enhance the company productivity. This algorithm has been tested using 3 size of population; 100, 1000 and 10,000. As a result, the speed of convergence is consistent and has not been affected through big population.N. N. S. Abdul Rahman, N.M. Saad, A. R. Abdullah, M. R. M. Hassan, M. S. S. M. Basir, N. S. M. Noor 1,2,4,6Faculty of Electronic and Computer Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia 2,3Center for Robotics and Industrial Automation, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia 3,5Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, MalaysiaLight rail transit (LRT), or fast tram is urban public transport using rolling stock similar to a tramway, but operating at a higher capacity, and often on an exclusive right-of-way. Indonesia as one of developing countries has been developed the LRT in two cities of Indonesia, Palembang and Jakarta. There are opinions toward the development of LRT, negative and positive opinions. To reveal the level of LRT development acceptance, this research uses machine learning approach to analyze the data which is gathered through social media. By conducting this paper, the data is modeled and classified in order to analyze the social sentiment towards the LRT development.Mohamad, S., Nasir, F.M., Sunar, M.S., Isa, K., Hanifa, R.M., Shah, S.M., Ribuan, M.N., Ahmad, A. 1,4,6,7,8Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, Johor, Malaysia 1,2,3UTM-IRDA Digital Media Centre, Media and Game Innovation Centre of Excellence, Universiti Teknologi Malaysia, Johor, Malaysia 1,2,3Faculty of Computing, Universiti Teknologi Malaysia, Johor, Malaysia 5Centre for Diploma Studies, Universiti Tun Hussein Onn Malaysia, Johor, Malaysia 6Research Centre for Applied Electromagnetics, Universiti Tun Hussein Onn Malaysia, Johor, MalaysiaReceived Jan 31, 2018 Revised Apr 21, 2018 Accepted Apr 30, 2018 Bluetooth is an emerging mobile ad-hoc network that accredits wireless communication to connect various short range devices. A single hop network called piconet is the basic communication topology of bluetooth which allows only eight active devices for communication among them seven are active slaves controlled by one master. Multiple piconets are interconnected through a common node, known as Relay, to form a massive network called as Scatternet. It is obvious that the performance of Scatternet scheduling is highly dependent and directly proportionate with the performance of the Relay node. In contrary, by reducing the number of Relays, it may lead to poor performance, since every Relay has to perform and support several piconet connections. The primary focus of this study is to observe the performance metrics that affects the inter-piconet scheduling since the Relay node’s role is like switch between multiple piconets. In this paper, we address and analyze the performance issues to be taken into consideration for efficient data flow in Scatternet based on Relay node.

Simulation of partial discharge within a void under square waveform applied voltage

Partial discharge (PD) activity within a void in a dielectric material is influenced by many factors. One of the factors is the applied voltage waveform on the material. In this paper, a two-dimensional (2D) model of a cylindrical void in polyethylene layers has been developed using finite element analysis (FEA) software. The model was used to simulate PD activity in the void under square waveform applied voltage. The obtained simulation results were compared with the measurement results from literature. It was found that both results are within reasonable agreement but with only slight disagreement. From comparison, critical parameters from the model affecting PD activity under square waveform applied voltage were identified; they include the inception and extinction voltages and electron generation rate. This finding may increase an understanding of PD behaviour within a void in a dielectric material under square waveform applied voltage.

The influence of absorbed gases on electroluminescence phenomenon in polymeric materials subjected to high electrical stress

Whenever a polymeric material is subjected to an electrical stress, imperfections such as protrusions, contaminants and microvoids, will all act as points where the field is enhanced, causing the degradation processes to be initiated. However, as manufacturing technology improves, insulation systems are of higher quality and their interfaces smoother. The reduction in concentration and size of impurities has led to more research at the atomic scale where space charges can play a fundamental role in triggering ageing phenomena. Since space charges seem to play a significant role in long-term electrical degradation of polymeric insulation, researchers are investigating the energy dissipation of mobile and trapped charges in the molecules of a dielectric medium. The dissipation process is associated with the emission of visible photons, a process known as electroluminescence (EL), which has been observed in various materials. This paper presents the series of experiments completed in the study of EL phenomenon in low-density polyethylene (LDPE); the most common type of material used for high voltage cable insulation. In addition to that, the role of gas diffusion into the polymer on the processes leading to EL has also been examined.